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3^^^^^B3t 



Marine Biological Laboratory Library 

Woods Hole, Mass. 



Presented by 

The liacmillan Company 
New York City 



An Introduction to Acarology 



I 



THE MACMILLAN COMPANY 

NEW YORK • BOSTON • CHICAGO 
DALLAS . ATLANTA . SAN FRANCISCO 

MACMILLAN AND CO., LIMITED 

LONDON . BOMBAY • CALCUTTA 
MADRAS . MELBOIRNE 

THE MACMILLAN COMPANY 
OF CANADA, LIMITED 

TORONTO 




Cunaxa /«//r?/.s (Kramer) 

THOMAS M. EVANS 



T 



An Introductio7i to 

ACAROLOGY 



Edward W. Baker^ 

BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 

AGRICULTURAL RESEARCH ADMINISTRATION 

UNITED STATES DEPARTMENT OF AGRICULTURE 

G. W. Wharton 

DEPARTMENT OF ZOOLOGY, DUKE UNIVERSITY 
DURHAM, NORTH CAROLINA 



THE MACMILLAN COMPANY 

JVew York 



Copyright, 1952, by The Macmillan Company 

All rights reserved — no part of this book may be reproduced in any 

form without permission in writing from the publisher, except by 

a reviewer who wishes to quote brief passages in connection 

with a review written for inclusion in magazine or newspaper. 

PRINTED IN THE UNITED STATES OF AMERICA 

First Printing 



To Our Friend and Teacher 
DR. HENRY ELLSWORTH EWING 

1883-1951 



PREFACE 




IN THE past few years there has been a growing demand for an ele- 
mentary and comprehensive work on mites, both from the pro- 
fessional acarologist and from students and investigators in related 
fields such as entomology, zoology, and parasitology. In the United 
States before 1940 there were only a few scattered workers in the 
field. Now, the interest created by the recognition of mites that carry 
human diseases and the problems created in agriculture by the use of 
DDT which causes heretofore unknown and undescribed species to 
become serious pests of plants have resulted in a growing list of both 
students and professional workers who have become interested in 
learning something about the Acarina. It is for these people that this 
book has been written. 

The German acarologist, Vitzthum, completed the section on Acari 
in Bronns' "Klassen und Ordnungen des Tierreichs" in 1942. While 
this work is comprehensive it is also exhaustive and does not present a 
digest of available knowledge for the beginner. Vitzthum's masterpiece 
has been extremely helpful to us, and we have followed his classifica- 
tion except in cases where our studies have indicated necessary changes. 
One of the most apparent deficiencies of Vitzthum's monograph for 
the beginner is its complete lack of keys and the absence of discussion 
of the Acarina family by family. 

The present book consists of a short introduction to the general 
structure, development, and ecology of mites in general and then each 
family is considered as a unit. We have prepared keys to the group that 
are designed to enable the reader to place any acarine in its proper 
family. In the discussion of each family the following information is 
given if it is known: a diagnosis, a list of genera and their type species 
(the reader is referred to S. A. Neave, 1939, "Nomenclator Zoologicus," 

vii 



for the citations to the genera) , a discussion which includes the biology, 
the economic or medical importance with emphasis on the species 
involved, and a series of references to pertinent literature. In addition 
line drawings of the representatives of the families are included. 

The Acarina are still poorly known even by specialists in the group. 
Therefore, it is anticipated that many changes will have to be made 
before a definitive work on the group is achieved. In many cases very 
little is known about certain famiHes. When it is realized that the 
Acarina represent an area for investigation in systematics, ecology, 
and economic zoology that is practically virgin territory, we can see 
that we are truly on the threshold of a new and exciting field. 

The authors wish to thank Drs. R. E. Beer, G. M. Kohls, H. H. J. 
Nesbitt, A. E. Pritchard, and R. W. Strandtmann for their helpful 
advice and crhicism. 

Edward W. Baker and G. W. Wharton 



TABLE OF CONTENTS 



Chapter I 


PAGE 


1 












lutrodudion 








History 




3 


Gnathosoma 


19 


Circulatory System 


29 


Collecting 




4 


Chelicerae 


21 


Respiratory System 


29 


Preparation for Study 


9 


Pedipalps 


23 


Nervous System 


30 


Terminology 




11 


Legs 


24 


Sense Organs 


31 


Metamerism 




11 


Muscles 


27 


Reproductive System 


33 


Integument 




13 


Digestive System 


27 


Life Cycle 


33 


Plates 




18 


Excretory System 


28 


Classification 
References 


34 
35 



Chapter II page 36 

The Suborder Oiiychopalpida Wharton, 1947 



Notostigmata With, 1903 
Opilioacaridae With, 1902 



36 Holothyroidea Reuter, 1909 38 

37 HolothyridaeThorell, 1882 38 



o67fc 



IX 



Chapter III page 40 

The Siihorder Mesostigmata G. Cajiestrini, 1891 



Megisthanina Triigardh, 1946 45 

Megisthanidae Berlese, 1914 45 

V Liroaspina Triigardh, 1946 46 

N/Liroaspidae Triigardh, 1946 47 

Epicriidae Berlese, 1885 48 

Microgyniina Tragardh, 1942 50 

Microgyniidae Tragardh, 1942 50 

Microsejidae Tragardh, 1942 51 

v^Gamasides Leach, 1815 52 

Discozerconidae Berlese, 1910 55 

Poecilochiridae Willmann, 1940 57 

v^ceosejidae N. F. 58 

•'Rhodacaridae Oiidemans, 1902 59 

Ixodorhynchidae Ewing, 1923 60 
Spelaeorhynchidae 

Oudemans, 1902 61 

Spinturnicidae Oudemans, 1901 62 

Ascaidae Oudemans, 1905 63 

•/ Veigaiaidae Oudemans, 1939 65 

Parasitidae Oudemans, 1901 66 

Macrochelidae Vitzthum, 1930 67 

Pachylaelaptidae Vitzthum, 1931 69 
Gamasolaelaptidae 

Oudemans, 1939 71 

Neoparasitidae Oudemans, 1939 72 

Pseudoparasitidae Vitzthum, 1941 74 

Raillietidae Vitzthum, 1941 75 

Halarachnidae Oudemans, 1906 76 

Entonyssidae Ewing, 1923 78 

RhinonyssidaeTrouessart, 1895 79 

Haemogamasidae Oudemans, 1926 82 

Dermanyssidae Kolenati, 1859 83 

s/phytoseiidae Berlese, 1916 87 

Iphiopsidae Kramer, 1886 90 

Laelaptidae Berlese, 1892 91 

Thinozerconina Tragardh, 1946 98 

Thinozerconidae Halbert, 1915 98 

Dasyponyssidae Fonseca, 1940 99 



Diarthrophallina 

Tragardh, 1946 102 

Diarthrophallidae 

Tragardh, 1946 102 

Zercoiiina Tragardh, 1944 104 

Zerconidae Berlese, 1892 104 

Trachytina Tragardh, 1937 105 

Trachytidae Tragardh, 1938 106 

Polyaspidae Berlese, 1917 107 

Polyaspinidae Tragardh, 1941 107 

Uropodina Kramer, 1881 108 

DiscourellidaeSellnick, 1926 110 

Coxequesomidae Sellnick, 1926 1 1 1 

Planodiscidae Sellnick, 1926 112 

Circocyllibanidae Sellnick, 1926 113 

Trematuridae Berlese, 1917 113 

Trematurellidae Tragardh, 1944 114 

Cillibidae Tragardh, 1 944 115 

Eutrachytidae Tragardh, 1 944 1 1 5 

Prodinychidae Berlese, 1916 116 

Urodiaspidae Tragardh, 1944 117 

Trachyuropodidae Berlese, 1917 118 

Phaulodinychidae Berlese, 1917 1 19 

Urodinychidae Berlese, 1917 120 

Uropodidae Berlese, 1917 121 

Celaenopsina Tragardh, 1938 123 

Diplogyniidae Tragardh, 1941 124 

Euzerconidae Tragardh, 1938 127 

Celaenopsidae Berlese, 1892 128 

Schizogyniidae Tragardh, 1950 129 

Fedrizziina Tragardh, 1937 129 

Parantennulidae Willmann, 1940 130 

Syngynaspidae Tragardh, 1938 131 

Cercomegistidae Tragardh, 1938 132 

Antennophoridae Berlese, 1892 133 

Paramegistidae Tragardh, 1946 134 

Fedrizziidae Tragardh, 1937 135 



Chapter IV page 137 

The Suborder Ixodides Leach, 1815 



ArgasidaeG. Canestrini, 1890 137 Nuttalliellidae Schulze, 1935 140 

Ixodidae Murray, 1877 141 



Chapter V page 146 

The Suborder Trombidiformes Reuter, 1909 



Tetrapodili Bremi, 1872 147 

EriophyidaeNalepa, 1898 147 

Tarsonemini Canestrini 

and Fanzago, 1877 159 

Podapolipodidae Oudemans, 1931 159 

Scutacaridae Oudemans, 1916 162 

Pyemotidae Oudemans, 1937 164 

Tarsonemidae Kramer, 1877 168 

Prostigmata Kramer, 1877 170 

Eupodidae Koch, 1842 174 

PenthalodidaeThor, 1933 177 

BdellidaeDuges, 1834 178 

Rhagidiidae Oudemans, 1922 181 

Cryptognathidae Oudemans, 1902 183 

Labidostommidae 

Oudemans, 1904 184 

Ereynetidae Oudemans, 1931 186 

Paratydeidae Baker, 1949 188 

Speleognathidae Womersley, 1936 189 

Tydeidae Kramer, 1877 190 

Cunaxidae Thor, 1902 193 

Lordalychidae Grandjean, 1939 195 



Sphaerolichidae Grandjean, 1937 
Nanorchestidae Grandjean, 1937 
Pachygnathidae Kramer, 1877 
Terpnacaridae Grandjean, 1939 
Alicorhagiidae Grandjean, 1939 
Raphignathidae Kramer, 1877 
Pomerantziidae Baker, 1949 
Pterygosomidae Oudemans, 1910 
Caeculidae Berlese, 1893 
Tetranychidae Donnadieu, 1875 
Phytoptipalpidae Ewing. 1922 
Teneriffiidae Thor, 1911 
Pseudocheylidae Oudemans, 1909 
Anystidae Oudemans, 1902 
Myobiidae Megnin, 1877 
Cheyletidae Leach, 1814 
Demodicidae Nicolet, 1855 
Erythraeidae Oudemans, 1902 
Smaridiidae Kramer, 1878 
Calyptostomidae Oudemans, 1923 
Trombidiidae Leach, 1815 
Trombiculidae Ewing, 1944 



196 
197 
199 
201 
202 
203 
206 
207 
210 
211 
220 
223 
224 
226 
229 
232 
235 
237 
241 
244 
245 
253 



XI 



Chapter VI page 259 

Hydrachnellae Latreille, 1802 



Halacaridae Murray, 1876 

Hydrovolziidae Thor, 1905 

Rhynchohydracaridae 

Lundblad, 1936 

Hydrachnidae Leach, 1815 

Limnocharidae Kramer, 1877 

Eylaidae Leach, 1815 

Protziidae Viets, 1926 

Hydrodromidae Viets, 1936 

Hydryphantidae Thor, 1900 

Clathrosperchonidae 

Lundblad, 1936 

Ctenothyasidae Lundblad, 1936 

Thermacaridae Sokolow, 1927 

Rutripalpidae Sokolow, 1934 

Mamersopsidae Lundblad, 1930 

Pseudohydryphantidae 

Viets, 1926 

Teutoniidae Lundblad, 1927 

Sperchonidae Thor, 1900 

Anisitsiellidae Viets, 1929 



269 

274 

275 
276 
277 
279 
280 
281 
282 

284 
285 
286 

287 
288 

289 
289 
290 
291 



Lebertiidae Thor, 1900 293 

Atractideidae Thor, 1902 294 

Pontarachnidae Thor, 1929 295 

Neotorrenticolidae 

Lundblad, 1936 296 

Limnesiidae Thor, 1900 297 

Hygrobatidae Koch, 1842 299 

Atractidellidae Lundblad, 1936 301 

Nautarachnidae Viets, 1935 303 

Feltriidae Thor, 1929 303 

Unionicolidae Oudemans, 1909 304 

Pionidae Thor, 1900 307 

Astacocrotonidae Thor, 1927 309 

Axonopsidae Viets, 1929 310 

Mideidae Viets, 1929 313 

Mideopsidae Thor, 1938 314 

Acalyptonotidae Walter, 1911 315 

A-Thienemanniidae 

Lundblad, 1930 316 

Eupatrellidae Viets, 1935 317 

Arrenuridae Thor, 1 900 317 

Krendowskiidae Lundblad, 1930 318 



Chapter VII page 320 

The Suborder Sarcoptifornies Renter, 1909 



Acaridiae Latreille, 1802 320 

Pediculochelidae 

Lavoipierre, 1946 325 

Saproglyphidae Oudemans, 1924 326 

Acaridae 

Ewing and Nesbitt, 1942 327 



Forcelliniidae Oudemans, 1927 337 

HyadesidaeHalbert, 1915 339 

Carpoglyphidae Oudemans, 1923 340 

Oulenziidae Oudemans, 1928 342 

Ensliniellidae Vitzthum, 1928 343 

Czenspinskiidae Oudemans, 1927 344 



Xll 



Winterschmidtiidae 

Oudemans, 1927 345 

Lardoglyphidae Oudemans, 1927 347 

Olafseniidae Oudemans, 1927 348 

Chortoglyphidae Berlese, 1897 349 

GlycyphagidaeBerlese, 1887 350 

Canestriniidae Berlese, 1884 353 

Hemisarcoptidae Oudemans, 1908 355 

Ewingidae Pearse, 1929 357 

Anoetidae Oudemans, 1904 358 

Linobiidae Oudemans, 1908 360 

Nanacaridae Oudemans, 1923 361 

SarcoptidaeTrouessart, 1892 362 



Cytoditidae Oudemans, 1908 366 

Laminosioptidae Vitzthum, 1931 367 

Heteropsoridae Oudemans, 1908 368 

Myialgesidae Trouessart, 1907 369 

PsoroptidaeCanestrini, 1892 370 

Epidermoptidae Trouessart, 1892 373 

Psoralgidae Oudemans, 1908 375 

Listrophoridae Canestrini, 1892 376 

Analgesidae Trouessart, 1915 379 
Dermoglyphidae 

Megnin and Trouessart, 1883 380 
Proctophyllodidae 

Megnin and Trouessart, 1883 384 



Chapter VIII page 387 

Oribatei Duges, 1833 



Palaeacaridae Grandjean, 1932 393 - 

Eulohmanniidae Grandjean, 1931 396 

NanhermaniidaeSellnick, 1924 397 

Epilohmanniidae Oudemans, 1923 398 

Lohmanniidae Grandjean, 1931 399 

- Hypochthoniidae Berlese, 1910 400 ~ 
Malaconothridae Berlese, 1916 403 

- CamisiidaeSellnick, 1928 403- 
HermanniidaeSellnick, 1928 404 
NeoliodidaeWillmann, 1913 405 

- Cymbaeremaeidae 

Willmann, 1931 406 ^ 

- BelbidaeWillmann, 1931 407 _ 
C Eremaeidae Willmann, 1931 408 ,.. 
^Carabodidae Willmann, 1931 412 

Ameronothridae Willmann. 1931 414 

- Hermanniellidae Grandjean, 1934 415 
Plateremaeidae Tragardh, 1931 416 -^ 



Liacaridae Willmann, 1931 417 

Zetorchestidae Michael, 1898 418 

Gustaviidae Willmann, 1931 418 

Oripodidae Jacot, 1925 419 

Tenuialidae Jacot, 1929 420 

Oribatulidae Jacot, 1929 420 

Ceratozetidae Jacot, 1925 423 

Oribatellidae Jacot, 1925 425 

Microzetidae Grandjean, 1936 426 

Notaspididae Oudemans, 1900 427 

Haplozetidae Grandjean. 1936 428 

PelopidaeEwing, 1917 429 

Galumnidae Grandjean, 1936 430 
Parakalummidae Grandjean, 1936 432 

Epactozetidae Grandjean, 1936 433 

Protoplophoridae Jacot, 1923 434 

Mesoplophoridae Jacot, 1923 435 

PhthiracaridaePerty, 1841 436 



Index PAGE 439 



Xlll 



CHAPTER I 



Introduction 



THE Acarina are to be found in almost every habitat available to 
animal life. Careful examination of the nearest handful of soil 
will surely uncover several (Figure 1), and in many localities literally 
thousands of specimens will be found. The feathers of birds are fre- 
quently alive with mites as are the pelts of animals. Many people carry 
a colony of follicle mites in their facial pores. Fresh water streams, 
lakes, and ponds have their mite faunas. The oceans are not free from 
them. Some mites are adapted to live in the hot water of springs that 
occur in certain volcanic regions. Insects, whatever their habitat, act 
as hosts for many species. Mites invade the internal organs of man and 
animals, both vertebrate and invertebrate. Most plants produce suit- 
able quarters, and examination of the debris from the fork of any tree 
will yield specimens. This world of life remains unknown to most men. 
Some zoologists and even some entomologists have never seen mites in 
their native haunts. Few of them appreciate the wealth of species that 
are at hand everywhere. 

Some of the Acarina, however, are known to the layman, and others 
frequently call attention to themselves by their activities. Ticks are well 
known to most people of the world because they are large enough to 
be seen readily with the naked eye and because frequently they attack 
man and his domestic animals. In the southern United States most 
people have had the misfortune to make the acquaintance of chiggers 
although few of them would recognize one as the larva of a mite. Fruit 
growers know the spider mites at first hand, and the eriophyids, an- 
other group of mites, are familiar to them. Many dog owners owe their 
introduction to the Acarina to mange-producing mites that attack their 
pets. People who work with stored food products, such as grain or 
copra, are at times aware of some of the mites that infest these prod- 

1 



2 A carology 

ucts because they produce an irritating itch. During periods of over- 
crowding such as occurred in England during World War II the hu- 
man-itch mite becomes prevalent and causes much suffering. While the 
activities of a few species are well known, people acquainted with their 
ravages can rarely recognize the mites if they see them. 

The small size of mites is responsible for the lack of information 




Figure 1 Mites removed from a small sample of litter and soil collected behind 
the Biology building at Duke University. This collection is representative of the 
acarid fauna found in humus. (Photo by Haliburton) 



Introduction 3 

available on them. The one suborder of the Acarina — the ticks — that 
is readily visible to the unaided eye is well studied. Students of ticks 
know them as well as the entomologists know the larger insects. They 
can be studied effectively without special techniques. A dissecting mi- 
croscope or even a high-powered hand lens will reveal the important 
taxonomic features. With other Acarina this is not the case. Techniques 
foreign to the entomologist must be used, and special methods of col- 
lecting are required. Specimens must be mounted on microscopic slides 
and studied under magnifications as high as one thousand diameters. 
Furthermore, the techniques are not the same as those used in various 
zoological sciences, although many special methods are borrowed from 
both zoology and entomology. The Acarina are not small enough to be 
handled like protozoans or soft-bodied enough to be treated as worms 
and they are too small to be studied like insects. Therefore they have 
been ignored by zoologists and entomologists alike. 

Many individuals would explain our lack of information on the 
mites on the basis of their relatively insignificant importance. This is 
not the case. At present many groups of mites that are of known 
economic importance are poorly understood. As knowledge of mites 
increases the vital, practical significance of many species will be rec- 
ognized. The science of acarology holds the same position today that 
entomology held fifty or one hundred years ago. 

History: Mites and ticks have been recognized for a long time. The 
early Greek writers were familiar with ticks and a few mites. In fact, 
Acari is the Latinized form of the Greek word for mite. By the time of 
Linnaeus, however, only about ninety species had been discussed in 
the literature, and the tenth edition of the "Systema Naturae" included 
only some twenty-nine species of mites in the genus Acarus. By 1850, 
however, many species were recognized. Oudemans 1926-1937 in his 
''Kritisch Historisch Overzicht der Acarologie" covers the literature up 
to and including 1850. Oudemans' work is invaluable to anyone de- 
siring information on early publications concerned with mites. 

From 1850 to the present time most work of a general nature has 
been done in Europe. Nalepa, G. and R. Canestrini, Berlese, Troues- 
sart, Hirst, Michael, Oudemans, Vitzthum, Thor, Tragardh, and others 
have made valuable contributions. Andre, Grandjean, Lundblad, 
Sellnick, Willmann, and Viets are still publishing important works. 
In the United States only two general acarologists have been active 
during most of the present century, although several have contributed 



4 A carology 

extensively on water mites, red spiders, oribatid mites, or other groups. 
Nathan Banks ranks as the first American acarologist, while his 
successor at the United States National Museum, the late Dr. Henry 
Ellsworth Ewing, contributed more on the Acarina than any other 
American. 

At present some twenty or thirty investigators in the United States 
are actively engaged in the study of the Acarina and the number is 
rapidly increasing. The United States government through its agencies, 
especially the Departments of Agriculture, Army, Navy, and United 
States Public Health Service, is becoming more interested in acarinids 
so that rapid development may be expected in the near future. 

Collecting: Mites are easy and at the same time difficult to collect. 
Because of their small size many are invisible in their natural habitats. 
For this reason, special techniques are required to capture them. Fre- 
quently the environment of the mites is collected in the field, and the 
mites themselves are apprehended in the laboratory; however, there 
are certain phases of the work that are the same for all. 

Collections are of little value unless records are made at the time of 
collection. The record should include the date, locality, name of the 
collector, a description of the habitat, and any pertinent remarks about 
temperature, humidity, and associated animals or plants that seem im- 
portant. In making an entry in a notebook it is well to remember that 
it is an easy matter to ignore irrelevant information that is recorded 
but practically impossible to recall relevant information that was not 
recorded because it did not seem important at the time. Each collec- 
tion must be clearly labeled so that the collector can easily correlate it 
with the appropriate notations in his notebook. 

Mites collected in the field may be preserved indefinitely in 85 per 
cent ethyl alcohol. They should be placed in small vials. Vials with 
over-all dimensions of 5 mm. by 28 mm. are obtainable from scientific 
supply companies. After alcohol, specimens, and label have been added 
to a vial it should be firmly stoppered with a cotton plug and put in a 
bottle of 85 per cent alcohol. When a vial has been filled it can be 
dropped into the stock bottle of alcohol for safekeeping. Another con- 
venient method is to use rubber-stoppered novacaine tubes (such as 
used by a dentist) that have been refilled with 85 per cent alcohol. 
Most dentists discard large numbers of these tubes, and they are 
usually willing to save them for a collector. 

Because of their small size, mites are difficult to handle. A mois- 



Introduction 5 

tened camel's-hair brush will be found helpful in the field. Water-color 
brushes sizes to 2 are best. Larger brushes are difficult to use. Al- 
though mites are small and fragile little injury to them results when 
they are picked up on the point of a brush. Iris forceps and dissecting 
forceps are helpful in manipulating the larger specimens and the small 
specimen vials. In picking up a mite with a pair of forceps it is desir- 
able to avoid using the tips of the forceps. If the mite is grasped be- 
tween the prongs of the forceps a few millimeters from the tip, usually 
no harm will come to the specimen since the tips of the forceps will 
come together first and thus protect the specimen when only light 
pressure is applied. 

Free-living terrestrial mites are usually found in collections of or- 
ganic debris, such as the upper layers of the soil. Many specimens will 
be found in the litter and litter-like accumulations found in cavities or 
forks of trees and bushes. Rotten logs and the soil beneath them are 
favored by some mites. The soil beneath rocks frequently produces 
soil-inhabiting species. Many plant feeders are to be found near the 
roots, leaves, and buds of plants or in the gills of many mushrooms. 
Beds of moss are usually very productive. Plants or parts of plants that 
appear abnormal should be particularly investigated. Most mites re- 
quire a moist environment. For this reason damp soil and debris will 
yield more specimens than dry. During wet weather many species that 
ordinarily live in the upper layers of the soil will be found in the 
litter. 

A white or black enamel or porcelain saucer or tray is helpful in 
examining material in the field. A small portion of the material to be 
examined is placed on the tray. It is then picked over bit by bit. Many 
mites will fall onto the tray where they will be visible against its shiny, 
smooth surface. Once detected, the specimen should be chased away 
from the debris and after it has cleaned itself it can be picked up with 
a cameFs-hair brush and placed in a vial. Any mites seen on the ma- 
terial in the tray should be forced out on a clean portion so that no 
debris is added to the vial. This precaution should be heeded especially 
when soil is being examined. Once a mite that has soil adhering to it is 
placed in alcohol it is practically impossible to cleanse it. The tray can 
be used in another manner also. Many mites, especially chiggers, will 
investigate any new object brought into their environment. Therefore, 
if the tray is placed on the ground and left for several minutes it will 
frequently acquire specimens that can be removed and placed into 
vials. 



6 A carology 

Mites will frequently adhere to flannel that is dragged past them. 
This method is particularly useful for collecting unattached ticks. The 
usual tick drag (Figure 2) is one yard square. It is made of flannel and 
its anterior end is tacked to a stick one yard long. A rope of convenient 
length is tied to the ends of the stick and the collector then pulls the 
drag slowly over the area to be investigated. At intervals the cloth is 
examined and the specimens removed with forceps or fingers. 




Figure 2 A tick drag in operation. 

By far the most efficient method of collecting terrestrial mites is that 
of bringing the environment into the laboratory for study. Number 5 
paper bags are useful. The environment' to be studied is placed in a 
bag; the top of the bag is then twisted and sealed with a rubber band. 
When very moist material such as damp moss is collected, oilsilk or 
rubberized cloth bags should be used. Once in the laboratory the ma- 
terial can be examined with the aid of a dissecting microscope or it can 
be run through a modified Berlese funnel. 

The modified Berlese funnel is the most useful tool available for 
separating mites and small insects from the debris in which they are 
found. Berlese funnels of many types have been designed (Figure 3). 
A suitable one for general collecting can be made simply. The funnel 



Introduction 7 

itself consists of a cone of sheet metal open at each end. The large 
opening should be about one foot in diameter while the small opening 
should not be greater than an inch in diameter. Such a cone should 
have an over-all length of eighteen inches. Three legs should be fas- 
tened to the cone so that it will stand upright with the small opening 
at the bottom. The legs should be sufficiently long so that a jar can be 
placed under the small opening. It is helpful to solder a metal screw 




Figure 3 A battery of Berlese funnels in use at Duke University. In the fore- 
ground are small funnels that are used to collect ectoparasitic mites. Two of 
them are in operation. The hosts are placed in small cages and the parasites are 
recovered from the water beneath the funnel. In the background are large fun- 
nels used to collect mites from debris. Notice the lights above each funnel for 
desiccating the material. (Photo Duke University by Whitley) 



cap to the cone at the lower end so that the collecting jar can be 
screwed into place. This reduces the chances of contamination of the 
collection from outside sources and prevents the escape of animals in 
the sample. A cover for the large upper opening should be made and 
fitted with an electric light bulb. Reflectors made to fit light sockets 
make exceflent covers. Larger or smaller funnels may be found more 
useful for special purposes. 



8 A carology 

Debris is wrapped in cheesecloth and placed in the funnel. The 
funnel is then tapped lightly to bring down any loose material before 
the collecting jar is in place. Once the jar is in place turn on the light 
and wait for the desiccation of the debris to force the mites to the 
bottom of the funnel. At times as many as three days will elapse before 
the debris in the funnel becomes completely desiccated. In this case 
specimens will continue to drop into the collecting jar for three days. 
When extensive collections are made a battery of Berlese funnels is 
required. Many species of mites and other arthropods will be found in 
the collecting jars. It is necessary to sort the specimens under a dis- 
secting microscope. 

In order to collect parasitic mites it is first necessary to collect their 
hosts. Almost all animals larger than mites are parasitized by them. 
Not only terrestrial but aquatic animals serve as hosts. While most 
parasitic mites are ectoparasites, some are endoparasites, and still 
others are social parasites. It is not possible to discuss at length pro- 
cedures for collecting all types of hosts. For this information the 
"Collectors' Manual" published by the Smithsonian Institution is rec- 
ommended. When collecting parasitic mites it must be remembered that 
proper identification of the host species is as important as identification 
of the mite. In order to identify the host properly it must be preserved so 
that it can be submitted to a speciahst for study. In collecting hosts of 
parasitic mites, large numbers of hosts should be obtained if a satisfac- 
tory survey is to be achieved. Fortunately mites do not leave their 
hosts upon their deaths as rapidly as do such insects as some fleas. 
For this reason snap traps are satisfactory for capturing mammals 
and other small, terrestrial vertebrates which serve as hosts for mites. 
The only satisfactory method of collecting birds is shooting. A dou- 
ble-barreled shotgun is to be preferred for this purpose so that both 
light and heavy shot will be available instantaneously. Hosts must be 
placed in mite-proof bags as soon as collected, so that parasites cannot 
crawl from one host to another. 

Examination of hosts in the laboratory is greatly facilitated by the 
use of a dissecting microscope. In examining a host the external sur- 
face should be thoroughly studied first. In the case of mammals and 
birds the fur and feathers make this difficult. With a little experience, 
however, it will be found that the skin can be exposed by careful ma- 
nipulation of the fur or feathers. In examining insects the wings, and 
the elytra in the case of beetles, must be unfolded. The areas of the body 
covered by the wings are favored by many ectoparasitic mites. Before 



Introduction 9 

investigating the internal organs the ear, eye, anal, and genital open- 
ings should be examined. Few mites are parasitic in the digestive tract 
of animals, but some are associated with the respiratory systems of 
both vertebrates and invertebrates. 

When animals suspected of harboring mites are brought into the 
laboratory alive, many of the ectoparasites can be collected without 
examining the host. Live hosts can be placed in cages that have wire 
or hardware cloth bottoms so that mites that fall off will drop through 
the floor of the cage. A suitable tray is placed beneath the cage from 
which the parasites can then be collected. Feces and urine of the host 
interfere frequently with this method but judicious feeding and fre- 
quent examination and cleaning can overcome this difficulty. 



Figure 4 A Birge net. (Photo by Parker) 

There are two useful tools for collecting free-living water mites. One 
is a smaff dip net with a narrow mesh bag with which mites that are 
visible in the water can be scooped up and the other is a Birge net 
(Figure 4). Water mites are to be found in practically all waters, but 
the best collecting sites for them are smaU lakes, streams, and ponds. 
In using the Birge net care should be exercised so that the bag remains 
expanded in the water. The net is designed to be used in weedy areas 
so that it snags infrequently. It is in the weedy areas along the shores 
that most water mites live. 

Preparation for Study: Ticks can be studied satisfactorily without 
mounting them on a glass slide. The taxonomic characters of ticks can 
best be made out if the tick is studied with the aid of a fairly high- 
powered dissecting microscope. 

Mites, on the other hand, must be prepared for examination by 
transmitted light and a compound microscope. Therefore they must 
be cleared and mounted on a glass slide. Many methods have been 



10 A carology 

used in the past and can be found in the hterature. Recently a new 
method has been evolved that is satisfactory for many mites. The 
directions for preparing and using polyvinyl alcohol (PVA) mounting 
medium follow: 

1. Dissolve "Elvanol" 71-24 (Du Pont polyvinyl alcohol) in four vol- 

umes of water by stirring at about 90 C. 

2. Filter the solution until it is no longer murky. 

3. Concentrate the clear filtrate on a water bath until it has the viscosity 
of Karo syrup. (A scum will form on the surface during the process 
of evaporation but will redissolve when stirred into the solution.) 

4. Add 22 parts of lactic acid to 56 parts of the PVA concentrate to 
make the finished mounting medium. 

5. Use like any mountant. Materials may be mounted directly from life, 
any aqueous solution, or alcohol. 

The large amount of shrinkage of PVA causes it to shrivel the soft- 
bodied mites (Tetranychidae) and to crush some of the larger, brittle 
ones (Oribatei). The solution should be used with discretion. 

In most cases, however, other methods are more useful. Temporary 
mounts may be made in any clearing agent such as glycerin, mineral 
oil, phenol, lactic acid, etc. Satisfactory permanent mounts can be 
made with aqueous solutions of gum arable, chloral hydrate, and 
glycerin. One of the best of the modified Berlese solutions is Hoyer's. 
At the United States National Museum specimens have been preserved 
in this for twenty years without deteriorating. It is an excellent medium 
for the Tetranychidae which are one of the more difficult groups to 
mount. The formula is: 

50 grams distilled water 

30 grams gum arable (clear crystals) 

200 grams chloral hydrate 

20 grams glycerin 

The ingredients should be mixed at room temperature in the above 
sequence. In the more humid areas, such as the Gulf States, the cover 
glass should be ringed to prevent absorption of moisture. Other ex- 
cellent Berlese mixtures are published but as yet the perfect mounting 
medium has not been found. 

Workers at the University of California have developed a metho- 
cellulose formula which has proved to be excellent for many mites. 
Their formula is: 



Introduction 1 1 

5 grams methocellulose 

2 grams carbowax 4,000 

1 milliliter diethylene glycol 
25 milliliters 95 per cent ethyl alcohol 
100 milliliters lactic acid 
25 milliliters distilled water 

They found the best procedure was to clear thoroughly in lactophenol 
before mounting, although some of the more delicate mites needed no 
special preparation as the lactic acid in the medium cleared the speci- 
mens sufficiently. 

Newell 1947 has devised a method for making permanent glycerin 
mounts. Untreated mites cannot be mounted satisfactorily in oil-solu- 
ble resins because the refractive indices of these substances are too 
close to those of the ectoskeletal elements of mites. If mites are 
mounted in such materials as damar or balsam they must first be 
cleared in lactic acid or mild caustic to remove the soft tissues. Their 
exoskeletons must then be stained so that they will contrast with the 
mounting medium. If a phase-contrast microscope is available, how- 
ever, unstained specimens can be studied satisfactorily in such mount- 
ing media. 

As soon as slides have been made they should be labeled. It is 
conventional to put the collection data on the right-hand label and 
reserve the left-hand label for the name of the mite. 

Terminology: Acarology has been developed largely as an outgrowth 
of entomology. Therefore the terms used in describing the anatomy of 
mites and ticks have been borrowed from entomology. Unfortunately 
entomological terms when applied to mites frequently have entirely 
different meanings from the term as originally used. Analogy rather 
than homology has been the usual criterion for transferring a term 
from one group to the other. It would be possible to create an entirely 
new vocabulary that applied properly to the Acarina, but this would 
create more confusion than now exists. Consequently names which 
have more or less general acceptance among acarologists will be used 
and will be defined as they apply to the Acarina without regard for 
their original entomological meaning. In most cases Vitzthum 1940 
will be followed. 

Metamerism: Many acarinids appear to consist of a single segment. 
Others have the body apparently divided into a cephalothorax and 



12 Acarology 

abdomen, and in some the abdomen appears to be segmented. Evi- 
dence of primary segmentation is found in the primitive Notostigmata. 
Some of the tarsonemids appear to have posterior segments but these 
are probably secondary rather than primary. 

Vitzthum 1940 divides the body of acarinids according to the fol- 
lowing chart (Figure 5) : 



Gnathosoma 

) Propodosoma — jj 
Metapodosoma 



Opisthosoma 




Region of the 
oral opening and 
the mouth parts 



Gnathosoma 



Figure 5 Schizotetranychus schiz- 
sopus (Zacher), 1913 showing the 
arbitrary divisions of the body. 
(After Vitzthum 1940) 



*Proterosoma 



Region of legs Propodosoma 
I & n 

Region of legs Metapodosoma 

III & IV 

Posterior region Opisthosoma 



Podosoma 



^Prosoma 



Idiosoma 



) 



\YiysX' 
J 



erosoma 



Andre and Lamy 1937 review the opinions on the primary metamer- 
ism of the acarinids and following Henking 1882 and Oudemans 1909 
state that there are thirteen metameres in most of the mites. The ven- 
tral parts of three segments are fused to form the gnathosoma. The 
first or pre-oral segment bears no appendages, the second bears the 
chelicerae, and the third the pedipalps. The podosoma consist of the 
dorsal parts of the first three segments and all of the next four seg- 



Introduction 13 

ments, each one of which bears a pair of legs. The opisthosoma is 
usually composed of six segments. Variation in the number of opis- 
thosomal segments is found and this accounts for variation in the total 
number of segments suggested above. The Notostigmata may have as 
many as ten or eleven opisthosomal segments. Pachygnathus may have 
eight or nine and Parhypocthonius has seven. 

The gnathosoma is usually set off from the rest of the body at least 
dorsally; but in some groups (Uropodina, Spelaeorhynchidae, Crypto- 
stigmatina, and others), the segments of the propodosoma extend over 
the gnathosoma and enclose it in a cavity or camerostome. In one fam- 
ily of the Prostigmata (Smaridiidae) the gnathosoma is protrusible on 
a long, narrow, trunklike stalk that may be as long as the mite itself. 
The gnathosoma is narrow and in no way can be said to correspond 
to the head of other arthropods. It is frequently called the capitulum, 
but the term gnathosoma is to be preferred since it bears only the 
mouth and mouth parts. 

The propodosoma with the first two pairs of legs is frequently sepa- 
rated from the metapodosoma by a deep furrow. The Trombiculidae 
exhibit this separation very well. It is for this reason that the gnatho- 
soma and propodosoma together are referred to as the proterosoma 
while the metapodosoma and opisthosoma which are usually fused in- 
sensibly with one another are designated as the hysterosoma. 

The prosoma corresponds to the cephalothorax of other arachnids 
but in no case are the anterior segments so fused that they form a 
distinct body region that can be designated as a cephalothorax in con- 
tradistinction to a posterior abdomen. However, Speleorchestes is 
exceptional in that the gnathosoma, propodosoma, metapodosoma, and 
opisthosoma are apparently each distinct from the others. 

The podosoma is that portion of the body that bears the walking 
legs. The idiosoma includes the body of the mite posterior to the 
gnathosoma. In many mites and all the ticks the only clearly recog- 
nizable body divisions are gnathosoma and idiosoma. 

Integument: As is the case with other arthropods the integument of 
the Acarina consists essentially of a single layer of epithelial cells, the 
hypodermis, and sclerotized layers which they secrete. The cuticle 
(Figure 6) can be subdivided into four distinct layers which are char- 
acterized by Vitzthum 1940 as follows: 

1. Tectostracum — the outermost covering which is always very thin and 
never pigmented 



14 



Acarology 



2. Epiostracum — the upper layer 

3. Ectostracum — the middle layer, usually pigmented with acid dyes 

4. Hypostracum — the inner layer, usually pigmented with basic dyes 




Figure 6 A section through the integument of Hyalomma marginatum hrioni- 
ciim Schulze and Schlottke, 1929 showing the two inner sclerotized layers, the 
ectostracum and hypostracum, with the hypodermis beneath them. (After 
Vitzthum 1940) 



The four layers are not recognizable in all acarinids. One or more 
of the chitinous layers may be absent or so combined with others that 
they are unrecognizable. In some cases the hypodermis itself may be 
so expanded by swelling of the opisthosoma, such as occurs in Pye- 
motes, that it is impossible to demonstrate it. 

Although the fundamental structure of the integument is similar in 
all species, the appearance, texture, and physical properties of the 
sclerotized coverings are varied and widely different from one group 
to the next. The Notostigmata possess a leathery, thin, granular cuticle. 

Many mites are completely or par- 
tially enclosed in heavy, armor- 
like sheaths. The Holothyroidea, 
many of the Mesostigmata, and 
the majority of the Oribatei are 
provided with hard, protective 
plates that enclose the entire 
body. The Trombidiformes and 
the Acaridiae have an elastic, 
transparent cuticle that may have 
hardened regions in the form of 
plates or setal bases. 

Much of the beauty of form 
and design resident in the struc- 
ture of the Acarina is to be found 
in the ornamentation of the cuti- 
Figure 7 The sternal plate of the ^j^ ^^-^^ -^ produced by pores, 
nymph of Parasitiis fuconim (De- ^ \ 

Geer), 1778. (After Vitzthum 1940) Tidges, folds, or pigment found 




Introduction 15 

in its various layers (Figure 7). The ornamentation of the cuticle is 
usually constant within species and is used in some groups to dis- 
tinguish them. 

Many special structures are derived from the cells of the hypoder- 
mis. There are various glands, setae, dyes, and special sensory organs 
formed wholly or in part by specialized portions of the hypodermis 
and its secretions (Figure 8). With the exception of the setae and 
hypodermal glands integumental derivatives will be considered under 
the organ systems to which they belong. 




Figure 8 Transverse section through the integument of Trombidiiim holo- 
sericeiim (Linnaeus), 1758. (After Vitzthum 1940) 

The integument of many acarinids is provided with glands. En- 
larged cells of the hypodermis pour their secretions directly out on the 
surface of most ticks. The water mites are well provided with glands 
that open in specialized areas over the body (Figure 9). These glands 
are more complicated than those of the ticks. Most of the Sarcopti- 
formes have a pair of oil glands that produce an oily fluid that is light 
yellow to deep brown in color. Similar glands have been found in a 
few of the Mesostigmata, e.g., Eulaelaps stabularis and Euhaemoga- 
masus horridus. 

The forms of setae are legion. As in most arthropods the setae serve 
many functions. They are tactile organs in that the nerves are so ar- 
ranged as to pick up pressure exerted on the setae. Some setae must 
also serve as organs of chemo-reception. Others actually protect their 
owners from attacks of predators in the same manner as the quills of 
a porcupine protect it. In many mites two fundamentally different types 



16 



Acarology 



of setae are recognizable: the setae proper, and the sensory setae 
which are obviously different from the majority of body setae. 

The setae proper ("Eigentliche Haare" of Vitzthum 1940, "Polls 
proprement dits" of Grandjean 1935) are of many types (Figure 
10). They may be simple, pilose, plumose, capitate, spatulate, cordate, 
palmate, pilidiform, pinnate, chambered, dentate, furcate, or may be 
so irregular that only a careful description will suffice for their identi- 




Figure 9 The arrangement 
of the integumental glands 
of Megaluracarus globator 
(Miiller), 1776. (After Vitz- 
thum 1940) 



fication. It is difficult to grasp the significance of the diversity of form 
exhibited by the setae. Their form and number in any species are 
usually constant. For this reason they are very useful as taxonomic 
characters. 

The primitive type of seta was most likely attenuate and pilose. The 
primitive arrangement of the setae corresponded with the primary 
segmentation of the animal, each segment being provided with a row 
of from two to six dorsal setae at its posterior margin. This primitive 
arrangement is maintained with little modification in certain of the 
Trombidiformes and Sarcoptiformes. In all of the larger groups, how- 
ever, reduction or multiplication of the setae has occurred many times 
so that the primitive arrangement is obscured in many species. 

The type of sensory seta most frequently seen is a striated sensory 



Introduction 



17 



seta that is probably a chemo-receptor. They are called "solenidien" 
by Vitzthum and "solenidions" by Grandjean. They are hollow and a 
living extension of the cells associated with them fills their lumen. They 
are directly connected with the peripheral nervous system. They are 
most commonly found on the distal segments of the appendages. 





,/% 




Figure 10 Types of body setae found on various mites. Top row; simple, pilose 
[Neocheyletiella rohweri Baker, 1949], plumose [Eiischongastia peromysci 
(Ewing), 1929], capitate [Spathulathrombiimi soiithcotti ( Womersley ) , 1935]; 
middle row: spatulate, cordate [Spathiilathromhium maximum Womersley, 
1945], palmate [Cheletogenes oniatiis (Canestrini and Fanzago, 1876)], pilidi- 
form [Holcotrombidium securigeriim (Canestrini), 1897]; bottom row: furcate 
[Hiotrombidiiim tubhi (Womersley), 1937], chambered [Camerotrombidium 
opulentiim (Womersley), 1945], and dentate [Acaropsis docta (Berlese), 1886]. 

In addition to the striated sensory setae, microsensory setae ("fam- 
ulus" of Grandjean 1935), are regularly found on the genu, tibia, and 
tarsi of the legs. Their function is not known but it is unlikely that such 
small structures would be tactile in nature. Whiplike setae ("acan- 
thoides" of Grandjean 1935), are ,also common on the legs. They 
differ from ordinary setae in being longer and nude. These setae might 
function as tactile organs. 

Certain setae are frequently associated with particular structures. 
Sensillae are setiform organs that arise from specialized pits, pseudo- 
stigmata, or sensillae bases, usually found on the propodosoma. The 
sensillae may be of almost any form but almost invariably they are 
readily distinguishable from the body setae. A specialized forked seta 
is found on the palpal tarsus of most of the IVTesostigmata. 



18 



Acarology 



Grandjean made a study of the nature of the chitin found in the 
setae of the different groups of mites. He found that certain of the 
setae of the Trombidiformes and Sarcoptiformes were optically active. 
The setae of these two groups were readily stained with iodine. The 
setae of the Mesostigmata and Holothyroidea were found to be opti- 
cally inactive and resistant to iodine. He designated the active chitin 
as actinochitin and included the Trombidiformes and Sarcoptiformes 
in one group, the Actinochitinosi; the Mesostigmata and Holothyroidea 
are combined as the Anactinochitinosi. Further study is required to 
determine the significance of a classification based upon the optical 
activity of the setae. 



Plates: The integument of most acarinids is not uniform in thickness. 

Certain areas are covered by much thicker layers than others and these 
heavy areas are the plates or shields. They corre- 
spond to the sclerites of insects but differ from them 
in that they usually extend over more than a single 
segment and in some cases may encompass the en- 
tire idiosoma. Furthermore, in most cases the plates 
found in the Acariha are not modifications of the 
primary sclerites but secondarily developed structures. 
None of the primary sternites remains unmodified. 
A vestige of the tritosternum remains, however, in the 
Notostigmata and the Mesostigmata as a peculiar 
seta-like structure in front of the sternal plate (Figure 
11). It consists of a basal portion that is usually un- 
paired from which a pair of pilose lacinae originate. 
In the Notostigmata the basal portion is paired while 
in the Uropodina the lacinae are fused basally but 
may be trifurcate distally. All other plates on the 
venter of the acarinids are secondary structures and 
not formed from the primary sternites. 

in a few mites all of the dorsal plates are in reality 
the modified tergites. They are readily recognizable 
in the Tarsonemini (Figure 12) and the hysterosomal 
plates of the Protoplophoridae and Mesoplophoridae 

can be traced back to the primary tergites. In the remainder of the 

mites only the propodosomal plate is a remnant of the primary tergites. 

It is formed by a fusion of the tergites of the segments of the first two 

pairs of legs; that is, segments iv and v. 




Figure 11 The 

tritosternum of 
Haemolaelaps 
traiibi (Strandt- 
mann), 1948. 
(After Strandt- 
mann 1948) 



Introduction 



19 




The propodosomal plate has been known under a variety of names 
in the different groups of mites. In the ticks and in larvae of the Trom- 
bidiidae, Trombiculidae, and related groups it is known as the scutum. 
In the adults of many of the Prostigmata it is called the crista metopica. 
In the oribatids that are capable of withdrawing the gnathosoma and 
legs into a cavity in the hystero- 
soma the propodosomal plate 
closes the opening like a trap door. 
In this group, the Ptyctima, the 
propodosomal plate is known as 
the aspis. The anterior portion of 
the dorsal plates or shield of other 
mites, or in some cases the entire 
dorsal plate, is in reality the 
propodosomal plate. 

The secondary plates or shields are formed in a number of ways. 
In the Pterygosomidae the setal bases become enlarged and fuse to 
form plates. The cuticle in the region of the genital and anal openings 
frequently thickens and thus anal and genital plates are formed. At 
times the cornea of the eyes will be supported at the periphery by a 
sclerotized ring that becomes enlarged to form an ocular plate. The 
integument may harden without apparent reason. Areas where glands 
open or muscles attach frequently develop into plates. In some groups 
sternal plates are formed by a fusion of the coxae, parts of which may 
sink below the surface to form internal apodemata. The arrangement 
of the secondary plates is quite different in different groups of mites 
and thus discussion of them must be considered separately for each 
group. 



Figure 12 Resinacariis resinatus Vitz- 
thum, 1927. A lateral view that shows 
the tergites. (After Vitzthum 1940) 



Gnathosoma: *The gnathosoma bears the mouth parts, the chelicerae, 
and the pedipalps. The mouth is hidden by the pedipalps and che- 
licerae. The gnathosoma is reduced in size and appears to consist only 
of its appendages and their projections. It is constructed in different 
ways in the different groups of mites; since fusion, expansion, and de- 
generation of its component parts have progressed in many ways, its 
relation to the rest of the body is not the same in all groups. At times 
the gnathosoma may be enclosed in a camerostome or cavity in the 
idiosoma, or it may form a prominent snout or beak. 

Dorsally the gnathosoma is usually covered, at least in part, by a 
tectum (Snodgrass 1948) or epistome as other authors call it. The 



20 



Acarology 



tectum is an anterior projection. It consists of a thin, chitinous plate 
that is usually toothed at its free end (Figure 13 ). The tectum may be 
so reduced in some mites as to be entirely lacking. 

The chelicerae originate below the tectum although they are at times 
covered by dorsal extensions of the pedipalps. These organs are so 
important that they will be considered later under a separate section. 




Figure 13 Tecta of various mites. Upper row, from left to right, Pergamasus 
olivaceus Vitzthum, 1927; Discopoma regia Vitzthum, 1921; Neopodocinum 
coprophiliim Vitzthum, 1926: lower row Trigonholaspis salti Vitzthum, 1930; 
Cyrtolaelaps capreolus Berlese, 1904. (After Vitzthum 1.940) 



Between and below the chelicerae is the mouth. The mouth is ven- 
tral to the labrum and dorsal to the hypostome. These structures may 
be elaborately developed, but they are seldom seen because their pres- 
ence is overshadowed by the pedipalps and chelicerae. Laterally the 
oral opening may be flanked by paralabra which may assist in closing 
the mouth and probably aid in directing food into the opening. In the 
Notostigmata and the Holothyroidea a toothed, radula-like organ de- 
rived from the labrum is associated with the oral opening. 

The pedipalps form the lateral-ventral surface of the gnathosoma. 
In some groups the basal expansions of the pedipalps extend medially 
and dorsally and fuse in the midline to form a tube in which the che- 
licerae are found. 

The hypostome forms the ventral-median wall of the gnathosoma. 
In most groups it is insensibly fused with the pedipalps but in the ticks 



Introduction 



21 



it can be seen as a toothed structure between the pedipalps (Figure 

14). The so-called hypostome of the ticks is not homologous to the 

hypostome of the other groups but is in reality 

formed largely from the pedipalps although its 

basal portion is formed in part by the true 

hypostome. 

Chelicerae: The chelicerae of the Acarina usu- 
ally terminate in a chela that is composed of a 
dorsaL fixed digit and a ventral, movable digit. 
In all of the suborders such chelate chelicerae 
are to be found. In the Notostigmata, Holo- 
thyroidea, and the Tetrapodili only chelate 
chelicerae are known. The chelicerae of the 
Tetrapodili are modified, however, in that the 
movable digit has become stylet-like and is 
the sole effective piercing element (Figure 15). 
The chela is formed from the tibia and tarsus. 
Fundamental segmentation of the chelicerae 
is obscure. In most arachnids the chelicerae con- 
sist of three segments. In some of the younger 
stages of certain mesostigmatids the chelicerae 
have six segments. In most other acarinids, how- 
ever, the chelicerae are divided into two or three 
segments. 

The primitive type of chelate chelicera is superficially similar in 
structure to the chelae of many decapod crustaceans. Each digit is pro- 
vided with teeth which may or may not oppose each other. This type 
of chela is used for grasping prey or crushing other types of food 
(Figure 16). In the males of many of the mesostigmatids the movable 
digit is modified as an accessory copulatory organ (Figure 17). It is 
used to transfer^ the spermatophores from the 
genital opening of the male to that of the female. 
Even though the movable digit is greatly modified 
the fixed digit is unchanged. 

The primitive chelate type is modified in many 
ways. Both elements may become minute and 
needle-like and together form a piercing structure 
such as is found in Dermanyssus (Figure 18). The 
fixed digit may disappear and the movable digit 




Figure 14 The hypo- 
stome of Ixodes rasiis 
Neumann, 1899. 




Figure 15 The che- 
licera of Eriophyes 
pini (Nalepa), 1887. 



22 Acarology 

may become terminal rather than lateral in position. The movable 
digit may become long and threadlike as it is in the spider mites. 
In the ticks the chelicerae are chelate but the movable digit is lateral 
rather than ventral and the teeth are on the outer surface of the chelae, 
not on the inner. The chelicerae of the ticks function as anchors and 
their structure is well adapted for this purpose (Figure 19). 

Special sense organs and setae are found on the chelicerae of many 
mites. At the base of the movable digit in some mesostigmatids an 




Figure 16 The chelicera of Para- 
situs fucorum (DeGeer), 1778. 
(After Vitzthum 1940) 




The chelicera of the 
male of Heterozercon audax Ber- 
lese, 1910. (After Vitzthum 1940) 



="^ 



Figure 18 The chelicera of Der- 
manyssus gallinae (DeGeer), 1778. 




Figure 19 The chelicerae of Ixodes reduvius (Linnaeus), 1758. Left, dorsal 
and ventral views of the male; right, dorsal and ventral views of the female. 
(After Vitzthum 1940) 



Introduction 23 

extension of the synarthrodia! membrane produces a pulvillus which 
resembles a cluster of setae in some cases or a coronet in others. There 
is frequently a seta at the tip of the fixed digit but not on the movable 
digit. Setae and sensory pores are found on the chehcerae of other 
groups as well. 

Pedipalps: The pedipalps are the second appendages in the arach- 
nids. In the Acarina they originate laterally from the palpal coxae 
which are probably homologous to the fused, basal segments of a 
primitive, biramous appendage. In recent Acarina the pedipalps are 
never divided into more than six segments, but in the Devonian Pro- 
tacarus crani Hirst there are seven segments. The segments of the pedi- 
palps are named as are those of the legs, beginning with the proximal 
element, as follows: coxa, trochanter, basifemur, telofemur, genu, tibia, 
and tarsus. The reduction in the apparent number of segments from 
the primitive seven to the maximum of six in living acarinids is accom- 
plished by fusion of the basifemur and telofemur to form an undi- 
vided femur. 

A relatively unmodified palp is found in the Onychopalpida, 
Mesostigmata, Cryptognathidae, Sarcoptiformes, Limnocharidae, and 
Eylaidae. In some of the above groups the palp is six-segmented but 
in all the tarsus and tibia are similar to those of the legs. The palpal 
tarsi of the Onychopalpida are provided with claws as are the tarsi of 
the legs (Figure 20). 





Figure 20 Right, the palpal tarsi of Neocarits texanus Chamberlain and Mulaik, 
1942 and left, the palpal tarsi of Holothyriis australasiae Womersley, 1935 to 
show the palpal claws. The setae have been omitted so that the claws are 
apparent. 



24 Acarology 

In addition to the simple, leglike pedipalps there are several impor- 
tant modifications. In some of the parasitic groups the pedipalps are 
reduced to vestigial knobs with specialized spines or angular projec- 
tions adapted to their parasitic habit. In the Trombidiformes the palpi 
may become enlarged and function as accessory chelicerae. 





Figure 21 The last two segments of Figure 22 The pedipalp of a 

the pedipalps of Euschongastia indica cheyletid mite. 

(Hirst), 1915. 

In some of the Trombidiformes the relationship between the palpal 
tarsus and palpal tibia is modified. The tibia is frequently provided 
with a terminal stout claw which displaces the palpal tarsus to a ven- 
tral position. A chelate pedipalp results from this displacement (Fig- 
ure 21). In its unmodified form the chelate pedipalp serves as a hand. 
The dorsal claw is opposed by the palpal tarsus or thumb and the mite 
is capable of picking up and holding not only its food but other ob- 
jects as well. 

In the Cheyletidae the chelate type of pedipalp is enormously de- 
veloped (Figure 22). The tibia is provided with a stout claw and the 
tarsus which has moved medially is also provided with cteniform or 
falcate, clawlike setae. In this group the right and left pedipalps oppose 
each other and form a powerful grasping organ with which to press the 
prey against the relatively minute chelicerae. The pedipalps of the 
Cunaxidae and Bdellidae function in a similar fashion but these lack 
the palpal thumb. 

Legs: The majority of the Acarina possess three pairs of walking legs 
in the larval stage and four pairs in all subsequent stages. The erio- 



Introduction 



25 



phyids have only two pairs of legs in all stages, and some of the Po- 
dapolipodidae and Phytoptipalpidae have either only three pairs of 
legs as adults or in some cases only a single pair. 

The legs, like the palps, are usually divided into six segments which 
extend from the body in the following order: coxa, trochanter, femur, 





Figure 23 A dorsal view of the tarsus 
I of Haemolaelaps glasgowi (Ewing), 
1925. 



Figure 24 Leg ii of the male of Para- 
situs bombophiliis Vitzthum, 1930. 
(After Vitzthum 1940) 



genu, tibia, and tarsus. Frequently the femur is divided into two seg- 
ments, the basifemur and the telofemur, so that seven segments are 
present. Fusion of the segments also occurs so that a five-segmented 
leg may occur or even a two-segmented leg as is found in Schizocarpus. 
In Chirodiscus legs i and ii consist of a single segment. In Tarsotomus, 
on the other hand, the tarsus may be.divided into as many as eighteen 
segments. 

The tarsi of the walking legs characteristically bear a pair of well- 
developed claws. In addition to the claws a delicate, transparent, 
sucker-like structure (the caruncle) may be present. A caruncle is 
regularly found on the tarsi of the Mesostigmata and Ixodides (Figure 
23 ) . In the Trombidiformes an empodium is frequently found between 
the two claws and in some cases the median empodium develops into 
a claw while the paired claws are reduced or modified to form tenent 



26 



A carology 



hairs. When the legs are modified so that they are no longer used for 
walking the claws are vestigial or absent. For example, the anterior 
pair of legs in the Macrochelidae are used as tactile rather than ambu- 
latory organs and the claws are either minute or absent. Many of the 
water mites that are active swimmers have no tarsal claws. 



^ ,^ 




rnf' 





Figure 25 An outline diagram of the Figure 26 A ventral view of leg i of 

male of Analges nitzschii HaWcr, IHIS Protomyobia claparedei (Poppe), 

to show the enlargement of legs iii. 1896 to show the roughened hair- 

(After Vitzthum 1940) grasping prominences. 



The legs are used primarily for walking and running but in certain 
groups they have other functions. The tactile and swimming legs have 
been discussed. Frequently the legs are used as graspers during copu- 
lation. The second pair of legs of many of the Parasitidae are strongly 
modified especially in the male (Figure 24). The males of the Anal- 
gesidae have exceptionally developed posterior legs (Figure 25 ) . They 
are so massive as to be useless as locomotor organs. The legs of water 
mites have many long, closely set setae that increase their surface in 
such a way as to make them efficient paddles. Some mites have certain 
pairs of legs modified as hair-grasping organs (Figure 26). The pos- 
terior legs of mites of the genera Spelorchestes and Nanorchestes have 
specialized muscles that enable the mites to jump quite effectively. Eu- 
podes with its enlarged femur iv is thought to be an effective jumper 
also. 

The coxae of the walking legs of many mites are immovable and so 
imbedded in the skin that they frequently form an endoskeleton. 



Introduction 27 

Muscles: Acarinids have striated muscles similar to those of other 
arthropods. The muscles extend into the appendages from the body 
and each leg is furnished with extrinsic as well as intrinsic muscles. 
The body musculature is well developed in many groups. The body 
muscles are responsible for the movement of the genital armature, the 
anal plates, and the gnathosoma. Muscles may originate or insert on 
plates, apodemata, epimera, or on the unspecialized, soft cuticle be- 
tween the plates. The origins and insertions of muscles can be detected 
externally because they frequently produce visible scars on the plates 
and dimple-hke concavities in the softer integument. In the soft-bodied 
mites the muscles are capable of changing the shape of the idiosoma. 

Digestive System: The digestive system of the Acarina is essentially 
a simple tube. The anterior portion or fore-gut is derived from the 
stomadaeum and consists of a muscular pharynx and tubular esopha- 
gus. The mid-gut or ventriculus is endodermal in origin and is charac- 
terized by a large lumen and a well-developed digestive epithelium. 
The hind-gut develops from the proctodaeum and can frequently be 
divided into an anterior, thin-walled, tubular intestine that in turn 
empties into a muscular rectum which opens to the outside through 
the anus. 

There are three fundamental types of digestive systems: 

1. A mesostigmatid type that is characteristic, of the Onychopalpida, 
Mesostigmata, and Ixodides 

2. A trombidiform type that is characteristic of the Trombidiformes 

3. A sarcoptiform type that is characteristic of the Sarcoptiformes 

The mesostigmatid type has a typical fore-gut composed of a mus- 
cular pharynx and a long, narrow esophagus that enters a small, central 
portion of the mid-gut. The mid-gut is characterized by a relatively 
small ventriculus from which large lateral diverticula arise. The intes- 
tine is long, except in the ticks, and it opens directly into a spherical 
rectum which connects with the anus. An ill-defined colon is present 
in the Notostigmata. Excretory tubules enter the hind-gut between the 
intestine and colon. 

The trombidiform type is characterized by the lack of colon and 
rectum. The fore-gut is typical in that the pharynx and esophagus are 
well developed. The ventriculus is large and its diverticula are broadly 
attached to it. The hind-gut in the Trombidiformes has been modified 
to form an excretory organ. Until recently most authors reported that 



28 Acarology 

there was no opening into the hind-gut from the ventriculus. Blauvelt 
1945 has demonstrated such an opening in a Tetranychus (Figure 27). 
The sarcoptiform type is more nearly Hke the parasitiform than the 
trombidiform. All of the divisions — pharynx, esophagus, ventriculus, 
intestine, colon, and rectum — are usually distinguishable. The body of 
the ventriculus is usually larger than its pair of posterior caeca. In this 
respect it differs widely from the mesostigmatid type. 




Figure 21 A longitudinal section through the body of a Tetranychus. (After 
Blauvelt 1945) 

A number of salivary glands empty on the gnathosoma near the 
mouth. These glands probably produce secretions which contain diges- 
tive enzymes. The larvae of many of the Trombidiformes can digest 
the cuticle of their hosts. In the spider mites certain of the glands pro- 
duce silk. The cells of the epithelial wall of the ventriculus and its caeca 
are glandular. They probably secrete digestive enzymes and it is prob- 
able that digestion and absorption occur principally in the lumen and 
cells of the mid-gut. The feces are formed in the intestine and are 
usually voided with the excretory products as tiny spheres. A secretion 
is used by the deutonymphs of certain uropodids to form an anal 
pedicel by which they attach themselves to larger arthropods, usually 
beetles. 

Excretory System: Three types of excretory organs are found in the 
Acarina. The most primitive is the coxal gland. Excretory tubules that 
open into the hind-gut but which are endodermal in origin are the most 
usual type. As previously mentioned the hind-gut of the Trombidi- 
formes becomes modified to form an excretory organ. In addition to 
these organs, the cells of the mid-gut are excretory in function. During 
digestion the cells become filled with excretory products that are cast 



Introduction 29 

off into the lumen of the mid-gut from whence they pass into the in- 
testine. Mites excrete their nitrogenous wastes in the form of guanin. 
The Notostigmata have two excretory tubules and a pair of coxal 
glands that open on coxae i or ii. The Holothyroidea have two pairs 
of excretory tubules and a pair of coxal glands that open on coxae i. 

The Mesostigmata have one pair of excretory tubules and from one 
to four pairs of coxal glands. 

The Trombidiformes have no excretory tubules of the usual type 
but the hind-gut is modified as an excretory organ in many of them. 
Coxal glands are present in some of the Trombidiformes. 

The Sarcoptiformes have a pair of small excretory tubes. Coxal 
glands have been found in the oribatids. 

Circulatory System: The circulatory system of most Acarina consists 
only of the blood, which is colorless and bathes all of the organs of the 
body. Amoeboid leucocytes are present and can best be demonstrated 
during the quiescent stages that precede ecdysis, A simple heart is 
present in the Holothyroidea and some of the Mesostigmata. 

Respiratory System: Of all the anatomical features of the Acarina, 
those associated with the respiratory system are most important to the 
systematics of the group. The suborders are established largely on the 
basis of this system. In those mites that have tracheae the number and 
placement of the stigmata are of first importance. In function the res- 
piratory system is similar to that of most terrestrial arthropods. The 
main tracheae are subdivided into tracheoles that run through most of 
the tissues and provide for the gaseous exchanges required by the 
metabolism of the cells. Some mites have no tracheal system. These 
mites are usually small, and respiration must be either carried on 
through the cuticle or by means of anaerobic reactions. 

The Notostigmata have four pairs of stigmata situated on the dorsal 
surface of the first four segments of the opisthosoma. They open 
through the leathery cuticle and are not supported by stigmal plates. 
Tracheal trunks branch out from each pair of stigmata but they do 
not anastomose. 

The Holothyroidea have two pairs of stigmata. The anterior pair is 
situated laterally above coxa iii. It communicates with a vestibule from 
which many tracheae extend out into the body tissues. The posterior 
pair of stigmata open into a pair of atria from which many thin-walled 
diverticula extend. 



30 Acarology 

The Mesostigmata and Ixodides have a single pair of stigmata in the 
aduhs, but in larval ticks there may be found several pairs of stigmata. 
The stigmata open into an atrium from which the tracheal trunks arise. 
Associated with the stigmata and trachea there is a chitinous tube, the 
peritreme. In the Mesostigmata the stigmata are situated ventrally lat- 
eral to the coxae and at the level of or in front of coxae in. The peri- 
tremes are usually long and anteriorly directed. They may be extended 
posteriorly for some distance as well and they may be almost straight 
or strongly bent. In the Ixodides the peritreme is never tubelike and is 
confined to the area adjacent to the stigmata that are placed behind or 
lateral to coxae iv. 

The stigmata of the Trombidiformes are usually situated on the 
gnathosoma or between the gnathosoma and the propodosoma. The 
females of the Tarsonemini have a pair or two pairs of stigmata on 
the proterosoma. Many males lack a respiratory system entirely. The 
Prostigmata have the stigmal openings on the gnathosoma and fre- 
quently stigmal horns or peritremes are present (Figure 28). The peri- 
tremes of the prostigmatids give rise to tracheal trunks and are not 
similar to the peritremes of the Mesostigmata. Many of the bdellids 
have a genital tracheal system in addition to the usual prostigmatic 
type. In a number of the smaller trombidiform mites stigmata and 
tracheae are reduced or wanting. 

The Sarcoptiformes lack tracheae and stigmata or have minute 
tracheae. The Acaridiae lack a specialized respiratory system. Most 
Oribatei are remarkable in that they have developed a system of 
tracheae that opens through stigmata and porose areas in many regions 
of the body. In this group even the pseudostigmata are associated with 
the respiratory system. Grandjean 1934 describes in detail the struc- 
ture of the respiratory system of this group. Some of the oribatids, 
however, lack respiratory openings and tracheae. 

Nervous System: Consolidation of the segmental ganglia has pro- 
gressed in the Acarina to such an extent that the central nervous sys- 
tem is an integrated mass surrounding the esophagus. In the embry- 
onic and larval stages fusion of the ganglia is not as complete as in the 
nymphs and adults. The portion of the brain dorsal to the esophagus 
gives rise to the nerves that supply the pharynx, chelicerae, and eyes. 
The nerves that run to the pedipalps, legs, and posterior internal organs 
all originate from that portion of the brain that is ventral to the esoph- 
agus (Figure 29). The nerves that run to the appendages do not sup- 



Introduction 



31 



ply other portions of the body. Apparently motor and sensory fibers 
are incorporated in all the nerves. 



Sense Organs: As with other arthropods the setae of the Acarina 
are primarily sensory in function. They have been discussed under the 
section on the integument with one exception. Many of the Trom- 
bidiformes and Sarcoptiformes possess specialized setiform, pseudo- 
stigmatic organs or sensillae. They usually arise from a specialized 





/1/^V^^ 



Figure 28 The emergent peritremes 
of Allothrombium sp. 



Figure 29 The brain of a Tetrany- 
chits. (After Blauvelt 1945) 



depression in the propodosomal plate or in the region of this plate if it 
is lacking. This depression is known as a pseudostigma and in the Ori- 
batei is connected with air sacs that aid in respiration. The function 
of the pseudostigma and its sensilla is unknown. That it is sensory is 
probably correct since the sensillae are directly connected to the nerv- 
ous system. The terrestrial mites that possess them usually have them 
well developed, but closely related aquatic groups have them reduced 
or lacking. Sensillae may vary in structure as widely as the body setae 
(Figure 30). They can be readily recognized in any one species be- 
cause they are always considerably different from the ordinary setae. 

The palps and legs of all acarinids are more or less thickly clothed 
with setae and in many cases are provided with striated, sensory setae. 
At times the palps or one or more pairs of legs are modified as tactile 
organs. The tarsi are usually well provided with special sensory setae 
and in the ticks and Rhagidiidae special organs have developed on the 
anterior tarsi. Haller's organ is characteristic of all stages of all ticks 
with the exception of Ceratixodes that lack it in the nymphal and per- 
haps also in the larval stage. Haller's organ is associated with the 
olfactory responses of ticks. It is situated on tarsus i and usually con- 



32 



A carology 



sists of a pit containing specialized setae (Figure 31). The Notostig- 
mata have a similar organ and the Mesostigmata have a concentration 
of setae on tarsus i similar to the setae of Mailer's organ. The Rhagi- 
diidae have well-developed "Rhagidia organs" on tarsi i and ii, and 
related groups have similar though not as highly modified structures. 

In the integument of most mites special areas consisting of pores, 
longitudinal clefts, or depressions that are supplied by nerves or are 
indirectly connected with the nervous system will be found. The func- 




Figiire 30 Sensillae of Trombicula 
(Eutrombicitla) alfreddiigesi (Oude- 
mans), 1910 and G alumna sp. 



Figure 31 A section through Haller's 
organ of Dermacentor veniistus Banks, 
1908. 



tion of these structures is unknown but they are probably sensory in 
nature. Mites respond to a number of stimuli for which no organs of 
special sense have yet been demonstrated. It is possible that these 
obscure organs respond to such stimuli. 

Eyes are present in many of the mites and many mites that lack 
them probably respond to changes in light intensity. The eyes of mites 
are never developed beyond the ocellus stage. Compound eyes are 
unknown in the Acarina. Mites that lack eyes usually have thin, trans- 
parent areas on the dorsal surface so that changes in light intensity will 
penetrate to the tissues below. The simplest eye consists of a concen- 
tration of pigment granules associated with an optic nerve. The pig- 
ment is frequently red but at times black or blue. Lenslike corneas are 
associated with the pigment granules in many cases. The most compli- 
cated eyes are found in certain of the water mites. Mites may have a 
single median eye or one or two pairs of propodosomal eyes or all five 
as is the case with many of the hydracarinids. Even the most compli- 
cated of eyes probably do no more than detect light intensity. It is 
doubtful that images are formed. 



Introduction 33 

Reproductive System: The Acarina are all dioecious. In most groups 
the males can be distinguished from the females even though males 
and females are similar to each other. Fertilization is internal, but the 
methods by which the spermatophores are introduced into the female 
reproductive system vary considerably. Some mites develop young 
parthenogenetically but none has been shown to be exclusively parthe- 
nogenetic. Mites may be oviparous or ovoviviparous. Only sexual repro- 
duction is known. 

The male reproductive system consists of a testis or pair of testes, 
vasa deferentia, accessory gland or glands, an ejaculatory duct, and a 
penis. The penis is lacking in the Mesostigmata where the spermato- 
phores are introduced into the female by the chelicerae. Many males 
have one or more pairs of legs modified as organs for grasping the 
female during copulation. 

The female reproductive system consists of an ovary or pair of 
ovaries, an oviduct, uterus, seminal receptacle, accessory glands, and 
in some cases a vagina. There is a specialized ovipositor in some 
groups (Oribatei), but usually the eggs are laid through the genital 
opening without the aid of an ovipositor. 

The genital openings of both males and females are usually closed 
by specialized plates that frequently have genital suckers associated 
with them or near them. In most mites examination of the genital 
opening is sufficient to distinguish the sexes but in some the presence 
or absence of a penis is the only reHable criterion, while in others 
examination of the gonads is required. 

The spermatozoa are frequently immature when transferred to the 
female and mature only after copulation is completed. Most mites 
develop one or a few eggs at any time but the ticks and some of the 
tarsonemids develop numerous eggs concurrently. 

Most eggs are provided with an eggshell that protects the developing 
embryo. In some cases eggs can be transported by wind currents for 
great distances. 

Life Cycle: The primitive life cycle consists of an egg in which the 
blastula develops, a deutovum formed by a chorion that is secreted by 
the blastoderm, a six-legged larva, a protonymph, deutonymph, trito- 
nymph, and adult males and females. So many families deviate from 
this primitive life cycle, however, that it is the exception rather than 
the rule. The life cycle of many of the mites is still to be determined. 
In most mites the larvae, except for the absence of the genital open- 



34 Acarology 

ings and the posterior pair of legs, are similar to the adults. In some 
prostigmatid mites the larva is quite different from the adult and in 
reality metamorphoses into the nymph. The nymphs are usually simi- 
lar to the adults. In the oribatids, uropodids, and the acarids, however, 
certain of the nymphs differ markedly from the adults. 

Classification: Most acarologists, entomologists, and zoologists con- 
sider the Acarina to be an order of the class Arachnida. As long as the 
Arachnida are subdivided primarily into orders this course reflects the 
relationships of the Acarina as well as any other. However, when cer- 
tain of the orders are grouped together into subclasses as is done by 
Petrunkevitch 1949 and others, it might seem desirable to consider 
the Acarina as a separate subclass. The Acarina are readily separable 
from other arachnids in that they possess a distinct gnathosoma. Fur- 
thermore they are never divided so that a distinct cephalothorax and 
abdomen are clearly recognizable. The phylogeny of the Acarina is 
obscure and most students of the group consider them to be polyphy- 
letic in origin. In the present work the Acarina will be considered as 
an order. 

A diagnostic classification of the Acarina follows: 

Phylum Arthropoda: Metameric animals with an exoskeleton and jointed 
appendages. 

Subphyliim Chelicerata: Arthropods without antennae or mandibles. 
Mouth parts consist of pedipalps and chelicerae. 

Class Arachnida: Chelicerates that lack gill books. 

Order Acarina: Arachnids with the mouth parts more or less dis- 
tinctly set off from the rest of the body on a false head, capitulum, 
or gnathosoma. Posterior segmentation is greatly reduced or absent. 
Primary sclerites are largely replaced by secondary plates of divers 
origins. Larval stages normally have three pairs of legs; nymphal 
and adult stages usually have four pairs of legs. Usually minute 
except for ticks and a few mites. 
Suborder Onychopalpida (Chapter II): Acarina with typical ambu- 
lacral claws on the pedipalps and more than one pair of idiosomal 
stigmata. 
Suborder Mesostigmata (Chapter III) : Acarina with a single pair of 
stigmata lateral to the legs that is usually associated with an elon- 
gated peritreme, or if absent degenerate parasites of the respiratory 
tract of vertebrates. Haller's organ absent. Hypostome not devel- 
oped for piercing. 



Introduction 35 

Suborder Ixodides (Chapter IV) : Acarina with a pair of stigmata 
posterior or lateral to the coxae associated with a stigmal plate 
rather than an elongated peritreme. Haller's organ present. Hypo- 
stome modified as a piercing organ and provided with recurved 
teeth. 

Suborder Tromihidiformes (Chapters V and VI) : Acarina with a pair 
of stigmata on or near the gnathosoma or absent. Palpi usually free 
and highly developed. Chelicerae usually modified for piercing. 
Anal suckers never present. 

Suborder Sarcoptiformes (Chapters VII and VIII) : Acarina without 
stigmata or with a system of tracheae opening through stigmata and 
porose areas on various parts of the body. Coxae forming apodemes 
beneath skin on venter of body. Mouth parts usually for chewing, 
with strong chelae; a few parasitic forms with specialized cheli- 
cerae. Palpi simple. With or without pseudostigmata and pseudo- 
stigmatic organs. Anal suckers often present. 

References: 

Banks, N. 1915. The Acarina or mites. U.S. Dept. Agric. Rpt. 108:1-153. 
Berlese, A. 1882-1903. Acari, Myriopoda, et Scorpiones hucusque in 

Italia reperta. Fasc. 1-101. Padua. 
Ewing, H. E. 1929. A manual of external parasites. 1-225 + xiv. Balti- 
more. 
Oudemans, A. C. 1926-1937. Kritisch Historisch Overzicht der Acarologie. 

(Volumes 1 and 2 supplements to Volumes 69 and 72 of Tijdschr. 

Ent. Leiden. Volume 3 published in six parts, independently.) 

1926. 850 V.C.-1758. 1:1-500 + vii. 

1929. 1759-1804. 2:1-1097 + xvii. 

1936-37. 1805-1850. 3:1-3379 + ci. 
Petrunkevitch, A. 1949. A study of Palaeozoic Arachnida. Trans. Conn. 

Acad. Art. Sci. 37:69-315. 
Radford, C. D. 1950. Systematic check list of mite genera and type species. 

Union Internat. des Sci. Biol., ser. C (sec. Ent.) 1 : 1-252. 
Reuter, E. 1909. Zur Morphologic und Ontogonie der Acariden. Acta Soc. 

Sci. Fenn. 36, No. 4:1-288. 
Snodgrass, R. E. 1948. The feeding organs of Arachnida including mites 

and ticks. Smithsonian Misc. Coll. 110, No. 10:1-93. 
Vitzthum, H. G. 1929. Acari. Die Tierwelt Mitteleuropas 3, No. 7:1-112. 

. 1931. Acari. Kiikenthals Handbuch der Zoologie. 3, 2 half: 1-160. 

. 1940-1942. Acarina. Bronns' Klassen und Ordungen des Tierreiches. 

5, Sect. 4, Book 5:1-1011 + xi. 



CHAPTER II 



Tlie Suhordei' Onychopalpida Wharton^ 1947 



MOST mites have such speciaHzed pedipalps that there are no 
palpal claws on the palpal tarsi, although some may have second- 
arily developed tibial claws. The groups Notostigmata and Holothy- 
roidea, that comprise the Onychopalpida are unique in that they possess 
reduced ambulacral claws on the pedipalps and a radula-like organ on 
the labrum. Although it is far from clear that these two represent a 
monophyletic group, their inclusion in a single suborder helps to 
emphasize their primitive nature and does set them apart as possibly 
representing living remnants of a former extensive fauna of primitive 
mites. 

Morphology: The palpal claws have already been mentioned. The 
suborder is also unique in that its members have at least four lateral 
stigmata. Because of the paucity of species no general account of the 
morphology of the group will be required to explain the key characters 
and is therefore omitted. For an account of the morphology With 1904 
and Grandjean 1938 are recommended. 

Key to the Onychopalpida 

1. With tritosternum, at least four pairs of dorso-lateral stigmata, 
two pairs of eyes, and leathery cuticle Notostigmata 

Without tritosternum, two pairs of lateral stigmata; no eyes, and 
sclerotized cuticle Holothyroidea 

NOTOSTIGMATA WITH, 1903 

Chamberlain and Mulaik 1942 erected the family Neocaridae to 
accommodate a new species of Notostigmata that they found in Texas. 

36 



Onychopalpida 



37 



While there is much justification for their action on the basis of mor- 
phology, it seems undesirable to recognize the familial separation that 
they suggest when so few species are represented in the group, as a 
whole. Therefore, only the single family Opilioacaridae is recognized 
here. 

Opilioacaridae With, 1902 
Figure 32 

Diagnosis: These are medium- 
sized mites about 1 mm. long, and 
oval in shape. The hysterosoma 
has indications of segmentation 
dorsally, the cuticle is striated with 
numerous minute pores, a divided 
tritosternum is present, two eyes 
are located on each side of the 
propodosoma, and the setae are 
simple or feathered. The pedipalps 
have reduced ambulacral claws 
while the chelicerae are unmodi- 
fied and a radula-like organ with 
recurved teeth is situated between 
and hidden by the chelicerae. The 
legs are segmented secondarily, 
trochanters in and iv are divided, 
the coxae are freely movable, and 
a pair of unmodified ambulacral 
claws is present on each tarsus. 
The genital openings of each sex 
are ventral between coxae iii, the 
females have an ovipositor, and 
the males have specialized areas 
lateral to the opening. On the dorsal-lateral aspect of the hysterosoma 
four pairs of stigmata are present, while a median stigma is present in 
Neocarus. 




Figure 32 Opilioacariis segmentatus 
With, 1902. Dorsal view of female 
showing the four pairs of opisthosomal 
stigmata. (After With 1903) 



Genera 
1. 



OpilioacarusWiih, 1902 {- Eucarus With, 1903) 
Type. Opilioacarus segmentatus Wiih, 1902 
Neocarus Chamberlain and Mulaik, 1942 
Type. Neocarus texanus Chamberlain and Mulaik, 1942 



38 Acarology 

3. Paracanis Chamberlain and Mulaik, 1942 

Type. Opilioacanis hexopthalmus Redikorzer, 1937 

Discussion: Although opilioacarids are primitive, they, like so many 
other primitive animals, have speciaHzed characteristics. The radula- 
like structure in the gnathosoma, the secondary segmentation of the 
legs, and the divided tritosternum are all considered to be evidence of 
specialization. 

Opilioacarids are secretive and live under stones and other debris. 
Chitinous remnants of other arthropods have been found in the gut of 
these mites. It appears Ukely therefore that they feed, at least in part, 
on small arthropods. These mites have been found in the Mediterra- 
nean area and Texas. So few specimens have been collected that rela- 
tively little is known of their life cycle. They are not known to be of 
economic or medical importance. 

References: 

Chamberlain, R. and S. Mulaik. 1942. On a new family in the Notostig- 

mata. Proc. Biol. Soc. Washington. 55:125-131. 
Grandjean, F. 1936. Un acarien synthetique: Opilioacanis segmentatiis 

With. Bull. Soc. Hist. Nat. Afr. Nord. 27:413-444. 
With, C. J. 1904. The Notostigmata a new suborder of Acari. Vidensk, 

Medd. fra den Naturk. Foren. i. Kbhvn. 1904:137-192 + Pis. iv-vi. 



HOLOTHYROIDEA REUTER, 1909 

The Holothyroidea is represented only by the family Holothyridae. 

Holothyridae Thorell, 1882 

Figure 33 

Diagnosis: The holothyrids are large (up to 7 mm. long) and hemi- 
spherical in shape but distinctly longer than broad. Evidence of pri- 
mary segmentation is lacking, and the body is divided into gnathosoma 
and idiosoma. The deep brown, smooth cuticle is heavily sclerotized 
in adults, eyes are absent, and the setae are of relatively unmodified 
form. Tarsal claws and five movable segments are located on the pedi- 
palps. The chelicerae are chelate. A radula-like organ is present on the 
tip of the labrum. The legs are all provided with paired ambulacral 
claws. In the midline between coxae iii and iv is located the genital 



Onychopalpida 39 

opening which is closed by two plates in the male and four in the 
female. 




Figure 33 Holothyrus longipes 
Thorell, 1882. Ventral view of 
the male. (After Hirst 1922) 



Genus: 

Holothyrus Gervais, 1842 

Type. Holothyrus coccinella Gervais, 1842 

Discussion: Species of Holothyrus are found in New Guinea, Ceylon, 
AustraUa, and islands in the Indian Ocean. The habits and life history 
of holothyrids are unknown. On Mauritius, Hirst 1922 records the fact 
that a Holothyrus is fairly common and that the irritant poison that 
they secrete is reported to cause the death of ducks and geese that 
swallow them. He also mentions that children suffer ill effects from the 
poison of these mites. 

References: 

Hirst, S. 1922. Mites injurious to domestic animals. Econ. Ser. British 

Mus. (Nat. Hist.). 13:1-107. 
Thon, K. 1906. Die aiissere Morphologie und die Systematik der Holothy- 

riden. Zool. Jahrb., Syst. 23:677-724 + Pis. 28-29. 
Womersley, H. 1935. A species of Acarina of the genus Holothyrus from 

Australia and New Zealand. Ann. Mag. Nat. Hist. 16:151-154. 



CHAPTER III 



The Suborder Mesostigmata G. Canestrini^ 1819 



THE Mesostigmata and Ixodides are usually combined to form a 
single suborder, the Parasitiformes. The evidence for this arrange- 
ment is good on morphological grounds, especially when the position 
of the stigmata and the structure of the gnathosoma are considered. 
However, two other suborders — the Trombidiformes and Sarcopti- 
formes — are apparently more closely related to each other than are 
the Mesostigmata and Ixodides. The relationship among these sub- 
orders, however, is not expressed in the classification. It seems desir- 
able for simplicity to omit the term Parasitiformes from the classifica- 
tion. This omission is not intended to deny relationship between the 
suborders but is made to increase the utility of the classification. 

The Mesostigmata are readily recognized by their gnathosoma, lat- 
eral stigmata, tritosternum, dorsal plates, ventral plates, genital open- 
ings, and legs. They are diverse in the details of their structure but are 
nevertheless a fairly compact group. Vitzthum 1931 estimated that 
there were 1,290 species at that time, but since 1931 numerous new 
species have been described. Even at present almost every small col- 
lection of mites contains a few new species of Mesostigmata. Since so 
many forms await discovery and description, the classification is of 
course in a state of flux. 

In a recent series of papers Tragardh has investigated the compara- 
tive anatomy of their sclerotized structures and has succeeded in ob- 
taining some degree of order out of the previous chaos. This has been 
achieved largely by studying the ventral plates of the females and the 
structures associated with the genital openings. Although his groups 
are established on the basis of the structure of females, his more recent 
investigations show that the ventral plates of the males may also be 
useful in demonstrating relationships. Despite Tragardh's excellent 

40 



Mesostigmata 41 

work much information concerning the Gamasides is needed before a 
satisfactory understanding of that group will be achieved. Of the 1,290 
species reported by Vitzthum 1939, 889 or more than 75 per cent 
belonged to the Gamasides. 

Tragardh follows the more commonly accepted classification of the 
Acarina and assigns the Mesostigmata to the rank of supercohort. In 
the present discussion Tragardh's supercohort will be considered a 
suborder. Tragardh's classification will be followed in spirit except 
that the names of the categories and some of his subdivisions will be 
omitted. 

Morphology: Mesostigmatid mites are usually well armored with 
brown to deep brown sclerotized plates or shields. In almost every case 
{Rhodacarus is an exception) the body consists of two distinct re- 
gions: an anterior, minute gnathosoma and a posterior idiosoma. In 
the Uropodina, one of the groups, the gnathosoma is frequently en- 
closed in a cavity (camerostome) in the idiosoma. 

With a little experience the general facies of mesostigmatid mites 
will enable the student to recognize more than 90 per cent of the spe- 
cies. However, all species that have either a tritosternum or one pair 
of lateral stigmata with a sinuate peritreme or both may be safely 
placed in the Mesostigmata. Of particular importance in the classifica- 
tion of the suborder is the distribution of the ventral plates, ventral 
setae, and ventral pores. Since Tragardh's classification is to be used 
his nomenclature for the structures will be used where applicable. 

The gnathosoma of mesostigmatid mites is a complicated apparatus. 
The chelicerae and the distal segments of the pedipalps are relatively 
unmodified, but the fused basal segments of the pedipalps that form 
the ventral wall are extended anteriorly and dorsally as several projec- 
tions and sheaths about the chelicerae. Dorsally an anterior projection 
extends over the gnathosoma and is called a tectum by Snodgrass 1948 
or epistome by other authors. In the. midline of the gnathosoma there 
is usually a groove that has markings reminiscent of recurved teeth. 
Lateral to the gnathosomal groove are the two main sections of the 
ventral wall of the gnathosoma. Anteriorly these are differentiated into 
a median hypostome, lateral cornua, and more medial paralabra. 

The legs of the mesostigmatids are usually well sclerotized. They 
typically have six or seven movable segments. The tarsi end in pre- 
tarsi that usually bear sucker-like caruncles and a pair of ambulacral 
claws. Tarsus i is frequently provided with a tuft of sensory setae on 



42 



Acarology 



the dorsal surface of the apex, but no pitUke Haller's organ, such as 
is found in the ticks, is present. (Haariov 1943). 

The idiosoma is armored with sclerotized plates. On the dorsal sur- 
face there is usually a single plate, but this may be completely or par- 
tially divided into two or more plates. Laterally there may be plates 
that connect the dorsal plate to the ventral plates, or lateral plates may 
be entirely lacking in which case soft, striated integument connects 
dorsal and ventral sclerites. 

Tritosternum 
Prestemal Seta 
Praeendopodal Plate 
Jugular Plate 
Peritremal Plate 
Para pedal Plate 
Endopodal Plate 
Sternal Plate 
Metasternal Plate 
Lateral Plate 
Epigynial Plate 
Metapodal Plate 
Ventral Plate 



Anal Plate 



Figure 34 A diagrammatic arrangement of the ventral plates that may be 
encountered in the Mesostigmata. A median plate, if present, will have the same 
position as the epigynial plate. 

The ventral plates are of extreme importance in recognizing the 
suborders (Figure 34). Just posterior to the gnathosoma in the mid- 
line there is the tritosternum. The tritosternum consists of a basal por- 
tion and two or three setiform distal processes. The tritosternum is a 
modified remnant of the sternal plates of the third segment and is the 
only relic of the primary stemites. Flanking the tritosternum there may 
be a pair of presternal setae and or praeendopodal plates that always 
lack setae. These plates are called jugular plates by Ewing 1928, but 
Tragardh reserves the term jugular for plates anterior to the sternal 
plate that bear sternal setae and may or may not have pores. Posterior 
to the tritosternum lies the so-called sternal plate. In some genera this 
plate bears four pairs of setae and three pairs of pores. The sternal 
plate is thought to have been formed by the fusion of coxal plates with 
the ventral body wall. The presence of four pairs of setae on some 




Mesostigmata 43 

sternal plates supports this hypothesis. At the other extreme the sternal 
plate may bear only two pairs of setae. In this case one pair of setae 
will be found on the jugular plates, while the fourth pair is on the 
metasternal plates just posterior and lateral to the sternal plate be- 
tween coxae III and iv. The most common arrangement is to have three 
pairs of setae and two pairs of pores on the sternal plate and the 
fourth pair of setae and third pair of pores on the metasternal plates. 
In the female the genital opening usually lies posterior to the sternal 
plate and between the metasternal plates. The female genital opening 
may be guarded by a median epigynial plate that may or may not bear 
setae; it may be flanked by setal-bearing lateral plates, or it may have 
both or neither of the plates. A median plate formed by sclerotization 
of the dorsal wall of the vagina may be present beneath the epigynial 
plate, or when the epigynial plate has been lost secondarily the median 
plate may be apparent on the surface as it is in the genus Fedrizzia. 
Posterior to the female genital opening is the ventral plate. The ven- 
tral plate bears setae and it may be found fused with either the epi- 
gynial plate or anal plate. Endopodal plates frequently occur between 
the coxae and the sternal plates. Parapodal plates occur lateral to the 
coxae. The stigmata and peritremes are sometimes located on special 
peritremal plates. Posterior to coxae iv and lateral to the ventral plate, 
metapodal plates are to be found. In the males the genital opening 
may be in the middle of the sternal plate or at its anterior border. As 
a rule much fusion is exhibited in the ventral plates of the males. 

Larvae of mesostigmatid mites have only three pairs of legs and 
reduced plates. Nymphs have four pairs of legs and can be readily 
recognized by the absence of genital openings. The dorsal plate of the 
nymphs is frequently broken into several platelets. The sternal and 
ventral plates, however, are usually fused to form a single ventral 
plate. 

Tragardh 1946 has achieved a sufficiently clear understanding of the 
comparative morphology of the group to be able to explain some of 
the relationships among the groups. Three of the groups lack an epi- 
gynial plate and show no evidence of a secondary loss of the plate. 
These three — the Megisthanina, Liroaspina, and Microgynina — com- 
prise one group. The other group in which either an epigynial plate 
or lateral plates or both are associated with the female genital opening 
is divided into eight groups: the Gamasides, Celaenopsina, Fedriz- 
ziina, Zerconina, Thinozerconina, Trachytina, Diarthrophallina, and 
Uropodina. 



44 Acarology 

A key to the groups of the Mesostigmata modified from Tragardh 
1946 follows: 

Key to the Mesostigmata 

1. Well-developed epigynial plate present in females, or if reduced 

or lacking its function taken over by median plate or lateral plates 2 

Epigynial plate primitively absent in females; median and lateral 
plates not closing genital opening 8 

2. Lateral plates present 3 
Lateral plates absent 4 

3. Discrete metasternal plates present Celaenopsina 
Metasternal plates combined in sternal plate Fedrizziina 

4. Epigynial plate hinged or fused to ventral plate along transverse 
suture, or peritreme ventral, or both 5 

Epigynial plate not articulated at base, peritreme dorsal 

Thinozerconina 

5. Epigynial plate with one pair of genital setae 6 
Epigynial plate without setae 7 

6. Male genital aperture surrounded by sternal plate; metasternal 
plates reduced so that only metasternal setae apparent; chelicerae 

of males not modified for copulation Zerconina 

Male genital aperture in front of sternal plate; metasternal plates 
varied; chelicerae of males more or less modified to transfer 
spermatophores during copulation Gamasides 

7. Metasternal plates distinct Trachytina 
Metasternal plates greatly reduced or lacking 10 

8. Presternal setae not present; female genital opening transverse slit 9 

Presternal setae flanking tritosternum; female genital opening 
crescentic fissure between sternal and ventral plates Megisthanina 

9. Female genital opening large, between sternal and ventral plates 

Liroaspina 

Female genital opening small, with no connection with either 
sternal or ventral plates Microgyniina 

10. Presternal setae flanking tritosternum Diarthrophallina 

Presternal setae not present Uropodina 



Mesostigmata 



45 



MEGISTHANINA TRAGARDH, 1946 

Only a single family is contained in the Megisthanina. There is little 
doubt, however, that it deserves group rank. Mites that belong to this 
group have a unique genital opening in that the sternal plate appears 
to function as an epigynial plate. 



Megisthanidae Berlese, 1914 

Figure 35 

Diagnosis: Megisthanids are large (from 1 to 
4 mm.) mites, oval in shape, and their bodies 
are divided into a gnathosoma and idiosoma. 
The cuticle is present with a single dorsal plate 
over the entire dorsum. The venter has an elon- 
gated ventral plate, and the sternal plate is 
divided into two parts, the posterior part of 
which resembles an epigynial plate. No eyes 
are present. A pair of presternal setae flank the 
tritosternum, the palps are unmodified, and the 
chelicerae are chelate and stout with strong 
teeth. Legs are stout with toothlike projections 
sometimes present on leg iv but there are no 
claws on leg i. The female genital opening is a 
crescent-shaped fissure placed just posterior to 

the sternal plate, while the male genital opening is located in the 
sternal plate aperture and is closed by two plates between which there 
is a transverse fissure. The stigmata are opposite the posterior legs 
and have elongated peritremes. 




Figure 35 Megistha- 
nus floridaniis Banks, 
1904. Ventral view of 
female. 



Genera: 
1. 



Megisthanus ThoreW, 1882 
Type. Megisthanus caudatus Thorell, 1882 
Celaenogamasus Berlese, 1901 
Type. Celaenogamasus hirtellus Berlese, 1901 
Cyclothorax v. Frauenfeld, 1868 
Type. Cyclothorax carcinicola v. Frauenfeld, 1868 
Hoplomegistus Berlese, 1903 

Type. Megistanus armiger Berlese, 1888 {Megistanus is a lapsus of 
Megisthanus) 



46 Acarology 

5. Stenosternum Kramer, 1898 

Type. Stenosternum bipilosiim Kramer, 1898 

Discussion: The diagnosis given above is based on the genus Megis- 
thanus. Vitzthum 1942 suggests that all of the genera may not agree 
with a diagnosis based on Megisthanus, but knowledge of the other 
genera is too limited for a definite statement to be made. Only the genus 
Megisthanus has been examined in preparing this work. 

Species of Megisthanus are commonly found on large beetles in 
moist environments. The best source of Megisthanus in the United 
States is the patent leather beetle, Popilius dis functus lUiger. The spe- 
cies found on this beetle is Megisthanus floridanus Banks. As far as 
is known, megisthanids are of little economic or medical importance. 

References: 

Tragardh, I. 1943. Further contributions towards the comparative mor- 
phology of the Mesostigmata (Acarina) the Antennophoridae and 
the Megisthanidae. Arkiv. for Zoologi. 34A. N:o 20:1-10. 

. 1946. OutHnes of a new classification of the Mesostigmata (Aca- 
rina) based on comparative morphological data. Lunds Universitets 
Arsskrift. N.F. Avd. 2. 42: No. 4:1-37. 

. 1946. Contributions towards the corriparative morphology of the 

Mesostigmata (Acarina) VII. The praesternal hairs and the male 
genital aperture. Sartryk ur Entomologsk Tidskrift. Arg. 67. Haft, 
3:88-108. 

LIROASPINA TRAGARDH, 1946 

The Liroaspina contains only two families of small mites that are 
similar to the Megisthanina and the Microgyniina in that they lack an 
epigynial plate. 

Tragardh 1946 in a study of the male genital openings recommends 
that the two families originally placed in the Liroaspina be further 
separated so that each is to be placed in a separate group. There is 
some justification for such a step since the male genital openings differ 
considerably. However, Tragardh's original plan of basing the classi- 
fication on the ventral plates of the females will be followed and thus 
the Liroaspina will not be split. 



Mesostigmata 



47 



Key to the Liroaspina 

1. Sternal shields in and iv fused to narrow, transverse shield; sternal 
shields i and ii free or fused in females; male genital aperture 
closed by nude, circular disk Liroaspidae 

Sternal shields ii, iii, and iv fused in female, i free; male genital 
aperture closed by two-piece circular disk bearing single pair of 
setae Epicriidae 



^v<^ 



Liroaspidae Tragardh, 1946 

Figure 36 
Diagnosis: The characteristic dis- 
tribution of the dorsal plates of 
liroaspids is diagnostic for the 
family. A single, large plate cov- 
ers most of the dorsal surface of 
the podosoma. At the posterior 
end there is an entire or divided 
pygidial plate that may or may 
not have posterior, setal-bearing 
projections. Between these two 
plates is a series of smaller plates 
and platelets. The sternal plates 
of the females are divided or par- 
tially fused. No epigynial plate is 
present. The male genital aper- 
ture is covered by a nude circular 
disk. It is situated near the anterior margin in the sternal shield. All 
tarsi are provided with pretarsi and claws. 




Figure 36 Liroaspis armatiis Fox, 
1947. Dorsal view of female. 



Genera and subgenera: 



1936) 



1. Liroaspis Banks, 1902 (= Dwigubskyia Oudemans, 
Type. Liroaspis americana Banks," 1902 

2. Berlesiana Turk, \9A3> 

Type. Epicriiis cirratus Berlese, 1917 

3. Epicroseius Berlese, 1904 
a. Epicroseius s. str. 

Type. Epicroseius augelioides Berlese, 1904 
h. I phidinychus Berlese, 1913 

Type. Echinoseius {Iphidinychus) manicatus Berlese, 1913. 
noseius is apparently only a lapsus for Epicroseius) 



(Echi- 



48 Acarology 

4. fr///mfl/7A2W Balogh, 1938 

Type. Willmannia sejiformis Balogh, 1938 

5. Zuliuicarus Tv'igkvdh, \906 

Type. Zuluacarus termitophilus Triigardh, 1906 

Discussion: Liroaspids have been found mostly in tropical countries, 
but species of Liroaspis have been collected in northern Europe and in 
the northern half of North America. The structure of their stout che- 
licerae indicates that they are predaceous. Specimens have been col- 
lected from plants, and Fox 1947 collected two specimens from two 
rats in Puerto Rico. The presence of Liroaspis armatus on rats does 
not necessarily mean that they are ectoparasitic on these hosts. They 
may have been on the rats purely by accident, or they may prey upon 
the large fauna of ectoparasites that infests rats. Except for their oc- 
currence on rats liroaspids are of no known economic or medical 
importance. 

References: 

Balogh, J. 1938. Systematische Studien iiber eine neue Milbengattung: 
Willmannia gen. nov. Zool. Anz. 123:259-265. 

Fox, I. 1947. Seven new mites from rats in Puerto Rico. Ann. Ent. Soc. 
America. 40:598-603. 

Tragardh, I. 1943. Further contributions towards the comparative mor- 
phology of the Mesostigmata (Acarina), the Antennophoridae, and 
the Megisthanidae. Arkiv. for Zoologi. 34A. N:o 20:1-10. 

. 1946. Outlines of a new classification of the Mesostigmata (Aca- 
rina) based on comparative morphological data. Lunds Universitets 
Arsskrift. N.F. Avd. 2. 42: No. 4:1-37. 

. 1946. Contributions towards the comparative morphology of the 

Mesostigmata (Acarina) VII. The praesternal hairs and the male 
genital aperture. Sartryk ur Entomologsk Tidskrift. Arg. 67. Haft. 
3:88-108. 

Epicriidae Berlese, 1885 

Figure 37 

Diagnosis: Epicriids can be readily recognized by the pattern of small 
elevations on the dorsal surface that gives the appearance of a fine 
geometrical network. The sternal plates of the females are divided so 
that sternal plate i is separated from plates ii, iii, and iv. The male 
genital aperture is situated in the sternal plate and is closed by a 



Mesostigmata 



49 



divided circular disk that bears a pair of setae. Epicriids are usually 
small (0,5 mm.) and golden brown in color. 












Figure 37 Epicriiis mollis (Kramer), 1876. Right, dorsal view of female; left, 
ventral plates of female. (After Tragardh 1942) 

Genera and subgenera: 

1. Epicrius G. Canestrini and Fanzago, 1877 

a. Epicrius s. str. 

Type. Gamasus mollis Kramer, 1876 (= Epicrius geometricus G. 
Canestrini and Fanzago, 1877) 

b. Diepicrius Berlese, 1916 

Type. Epicrius {Diepicrius) parisiensis Berlese, 1916 

2. Cor nubia Turk, 1943 

Type. Cornubia ornata Turk, 1943 

Discussion: Epicriids are usually found in moss or accumulations of 
plant roots or rhizomes. On Guam Epicrius sp. was found among the 
rhizomes of epiphytic ferns that live in the tops of the trees of the rain 
forest. Epicriids are not known to be of any economic or medical 
importance. 



References: 

Tragardh, I. 1942. Zur Kenntnis der Gattung Epicrius Berlese (Acarina). 

Arkiv. for Zoologi. 34A. N:o 4:1-10. 
. 1943. Further contributions towards the comparative morphology 

of the Mesostigmata (Acarina) the Antennophoridae and the Megis- 

thanidae. Arkiv. for Zoologi. 34A. N:o 20:1-10. 



50 



Acarology 



-. 1946. Outline of a new classification of the Mesostigmata (Acarina) 
based on comparative morphological data. Lunds Universitets Ars- 
skrift. N.F. Avd. 2. 42: No. 4:1-37. 

-. 1946. Contributions towards the comparative morphology of the 
Mesostigmata (Acarina) VII. The praesternal hairs and the male 
genital aperture. Sartryk ur Entomologsk Tidskrift. Arg. 67. Haft. 
3:88-108. 



MICROGYNIINA TRAGARDH, 1942 




Figure 38 Microgynium rectangii- 
latiim Tragardh, 1942. Ventral view 
of female. (After Tragardh 1942) 



This group was recognized as a 
cohort by Tragardh and was erected 
to contain two new species found by 
Forsslund in Sweden. Each species 
was recognized by Tragardh as rep- 
resenting a new genus and family. 
The sub-order is characterized by 
Tragardh as follows: the male genital 
aperture is located in the sternal 
shield and is not ring-shaped; the 
plate is not segmented and is di- 
rected forwards. The female genital 
aperture is a small transverse fissure 
placed far back without any connec- 
tion with either the sternal or ventral 
plates. Three or four dorsal shields 
are present. The peritreme is short 
and tarsus i lacks a peduncle. 



Key to the Microgyniina 

1. Dorsal side with three plates; ventral plate of female divided 
longitudinally Microgyniidae 

Dorsal side with four plates; ventral plate of female entire 

Microsejidae 

Microgyniidae Tragardh, 1942 

Figure 38 

Diagnosis: Microgyniids are small (0.3-0.4 mm.), colorless to fight 
yellowish brown mites with three dorsal plates and a divided ventral 
plate in the female. 



Mesostigmata 



51 



Genus: 

Microgynium Tragardh, 1942 

Type. Microgynium rectangulatum Tragardh, 1942 

Discussion: M. rectangulatum was found under the loose bark of old 
tree stumps. Larvae, nymphs, males, and females were collected. Only 
one nymphal stadium was described. These mites are of no known 
economic or medical importance. 

References: 

Tragardh, I. 1942. Microgyniina, a new group of Mesostigmata. Ento- 
mologisk Tidskrift Arg. 63. Haft. 3-4:120-133. 

. 1943. Further contributions towards the comparative morphology 

of the Mesostigmata (Acarina) the Antennophoridae and the Megis- 
thanidae. Arkiv. for Zoologi. 34A. N:o 20:1-10. 

. 1946. Outlines of a new classification of the Mesostigmata (Aca- 
rina) based on comparative morphological data. Lunds Universitets 
Arsskrift. N.F. Avd. 2. 42: No. 4:1-37. 

. 1946. Contributions towards the comparative morphology of the 

Mesostigmata (Acarina) VII. The praesternal hairs and the male 
genital aperture. Sartryk ur Entomologsk Tidskrift. Arg. 67. Haft. 
3:88-108. 

Microsejidae Tragardh, 1942 

Figure 39 



Diagnosis: The microsejids are 
similar to the previous family but 
differ in that there are four dorsal 
plates and an undivided ventral 
plate in the female. 



Figure 39 Microsejus truncicola Tra- 
gardh, 1942. Ventral view of female. 
(After Tragardh 1942) 




52 
Genus: 



Acarology 



M/cravf/7/5 Tragardh, 1942 

Type. Microsejus truncicola Tragardh, 1942 

Discussion: These mites are found under the loose bark of tree 
stumps. Only nymphs and adults are known. They are of no known 
economic or medical importance. 

References: 

Tragardh, I. 1942. Microgyniina, a new group of Mesostigmata. Ento- 
mologisk Tidskrift Arg. 63. Haft. 3-4:120-133. 

. 1943. Further contributions towards the comparative morphology 

of the Mesostigmata (Acarina) the Antennophoridae and the Megis- 
thanidae. Arkiv. for Zoologi. 34A. N:o 20:1-10. 

. 1946. Outlines of a new classification of the Mesostigmata (Aca- 
rina) based on comparative Morphological data. Lunds Universitets 
Arsskrift. N.F. Avd. 2. 42: No. 4:1-37. 

. 1946. Contributions towards the comparative morphology of the 

Mesostigmata (Acarina) VII. The praesternal hairs and the male 
genital aperture. Sartryk ur Entomologsk Tidskrift. Arg. 67. Haft. 
3:88-108. 



GAMASIDES LEACH, 1815 

Gamasid mites are among the commonest type found in most col- 
lections, whether from debris or as ectoparasites of vertebrates or 

invertebrates. Since the monu- 
mental works of Berlese, no au- 
thor has achieved a really clear 
understanding of this vast assem- 
blage of species. The classifica- 
tion of the group that follows is 
largely taken from Vitzthum 
1941. 

Of special value in the classifi- 
cation of these mites is a forked 
Figure 40 The specialized setae on seta at the base of the palpal 
the palpal tarsus of a laelaptid (left) tarsus (Figure 40). Those species 
and non-laelaptid (right) mite. The ^j^^^ ^^^^ ^^^^ ^^^^ ^^^ ^^^^^ ^^ 
other setae on the palpal tarsus have ,-, i i i • 

been omitted. ' the seta can readily be placed mto 





Mesostigmata 53 

their respective families, but those with only two tines are more 
difficult. 

Gamasids can be recognized readily in the males because the che- 
licerae are more or less modified to function in the transfer of sper- 
matophores to the females and the male opening is anterior to the 
sternal plate. The females are recognized by the characteristic arrange- 
ment of the ventral plates as described by Tragardh 1946. The lateral 
plates are absent, and the metasternal plates are either free and fused 
with the corresponding endopodal plates, or small, or fused with the 
sternal plate. The epigynial plate bears a pair of setae and it may or 
may not be fused with the ventral plate. 

Key to the Gamasides 

1. Lacking large bell- or bucket-shaped suckers at sides of anal open- 
ing 2 

With large bell- or bucket-shaped suckers at sides of anal open- 
ing Discozerconidae 

2. Male genital opening at anterior margin of sternal plate; no dark 
transverse bands on sternal plate of nymph 3 

Male genital opening in special presternal plate; sternal plate 
usually with dark transverse band in nymph Poecilochiridae 

3. Females without jugular plates; copulatory suckers absent in male 4 

Females with jugular plates; copulatory suckers on raised cone of 
ventroanal plate Aceosejidae 

4. Podosoma and opisthosoma insensibly fused; no constriction be- 
tween the two regions 5 

Body elongated; opisthosoma separated from podosoma by deep 
furrow Rhodacaridae 

5. Lateral, ventral, anterior projections of pedipalpal coxae not har- 
poon-shaped; chelicerae chelate or stylettiform 6 

Females with lateral, ventral, anterior projections of pedipalpal 
coxae harpoon-shaped; chelicerae without fixed digit; movable 
digit with large, recurved teeth Ixodorhynchidae 

6. Base of gnathosoma forms narrow sheath for chelicerae 7 

Base of gnathosoma forms broad cavity or camerostome that 
encloses chelicerae but not palps Spelaeorhynchidae 

7. Coxae movable 8 



u^ 



54 Acarology 

Coxae immovable, arranged radially; legs stout; parasitic on bats 

Spinturnicidae 

8. Forked seta on palpal tarsus with more than two tines 10 
Forked seta on palpal tarsus with two tines 9 

9. Dorsal plate entire or divided into large anterior and small pos- 
terior plate 16 

Dorsal plate divided into two subequal plates that cover most of 
dorsum Ascaidae 

10. Forked seta on palpal tarsus with three tines 11 
Forked seta on palpal tarsus with four tines Veigaiaidae 

11. Epigynial plate without pointed apex thrust between pair of meta- 
sternal plates 12 

Epigynial plate with pointed apex thrust between pair of meta- 
sternal plates Parasitidae 

12. Leg I similar to other legs 13 

Leg I reduced, thin, without typical pretarsus, caruncle, or claws 

Macrochelidae 

13. Females with parapodal, peritremal, and metapodal plates not 
fused and not extending posteriorly lateral to ventral plate or all 
lateral plates fused with ventral plate 14 

Parapodal, peritremal, and metapodal plates fused and extend be- 
hind coxae IV lateral to ventral plate Pachylaelaptidae 

14. Dorsal plate entire 15 
Dorsal plate divided into two Gamasolaelaptidae 

15. Pretarsus and caruncle of leg i similar to those of other legs 

Neoparasitidae 

Pretarsus and caruncle of leg i reduced, not like other legs 

Pseudoparasitidae 

16. Tritosternum present with lacinae in females 20 
Tritosternum absent or reduced without lacinae in females 17 

17. Chelicerae reduced or non-chelate except for few parasites of nasal 
cavities of birds; males without apophyses on leg ii 18 

Chelicerae chelate; parasites in the external auditory meatus of 
cattle and antelopes; basal portion of tritosternum reduced or lack- 
ing in females, males with apophyses on leg ii Raillietidae 



Mesostigmata 55 

18. Body shape oval; genital plate of female may be fairly well de- 
veloped; parasites in respiratory passages of birds and snakes 19 

Body shape elongated oval to wormlike; genital plate of female 
rudimentary or lacking; parasites in lungs of mammals 

Halarachnidae 

19. Dorsal plate undivided and covering more than podosoma, or if 
podosomal in position truncate posteriorly with a pair of long 
setae at its posterior border; parasitic in lungs of snakes 

Entonyssidae 

Dorsal plate usually divided or restricted to podosoma; parasitic 
in nasopharynx of birds Rhinonyssidae 

20. Setae over body sparse; tectum not shaped like tongue, not pro- 
vided with long lateral teeth 21 

Setae numerous over body resembhng a pelage; tectum shaped like 
tongue with long lateral anteriorly directed teeth Haemogamasidae 

21. Chelae reduced Dermanyssidae 
Chelae not reduced 22 

22. Epigynial plate drop-shaped, may be excavated posteriorly to 
accommodate anal plate 23 

Epigynial plate truncate or concave posteriorly Phytoseiidae 

23. Peritreme extremely short, less than five times diameter of stigma 

in length Iphiopsidae 

Peritreme long, more than five times diameter of stigma in length 

Laelaptidae 



Discozerconidae Berlese, 1910 

Figures 41a, b 

Diagnosis: The key character — the presence of large bell-shaped 
suckers flanking the anus — at once distinguishes members of this fam- 
ily from all others. Even in the absence of the suckers, however, these 
mites are readily separable from other gamasids in that the sternal 
plates are divided into a pair of anterior laterals and a pair of posterior 
laterals fused with the endopodal plates. All tarsi have pretarsi, carun- 
cles, and small to vestigial claws. Body setae are extremely short and 
stout. 



56 



Acarology 



Genera: 

1. Discozercon Berlese, 1910 

Type. Discozercon mirabilis Berlese, 1910 

2. Allozercon \iizXhum, \926 

Type. Allozercon fecundissiinus Vitzthum, 1926 

3. Atacoseius Berlese, 1905 

Type. Atacoseius pellucens Berlese, 1905 

4. Discomegistus Tvdigkrdh, 1911 

Type. Discomegistus pectinatiis Tragardh, 1911 

5. Heterozercon Berlese, 1888 

Type. Heterozercon degeneratus Berlese, 1888 





Figure 41 a Heterozercon oiidemansi 
Finnegan, 1931. Ventral view of fe- 
male. (After Finnegan 1931) 



Figure 41 h Discozercon mirabilis 
Berlese, 1910. Ventral view of female. 
(After Berlese 1914) 



Discussion: The placement of Atacoseius in the family is somewhat 
doubtful since the type species is known only from immature speci- 
mens that do not exhibit all of the characteristics of the family. Vitz- 
thum reports that Berlese proposed the family Heterozerconidae for 
the group in 1892, but a search to verify his report was unsuccessful. 
The discozerconids are ectoparasites of large millipedes, centipedes, 
termites, snakes, and some are free-living or at least have been found 
unassociated with a host. All of the species are tropical or subtropical 



Mesostigmatu 



57 



in distribution. None is known to be of medical or economic impor- 
tance. 

References: 

Berlese, A. 1910. Brevi diagnosi di generi e specie nuovi di Acari. Redia 

6 (2): 346-388. 
Finnegan, Susan. 1931. On a new species of mite of the family Heterozer- 

conidae parasitic on a snake. Proc. Zool. Soc. London 1931: 1349- 

1357. 
Vitzthum, H. G. 1926. Malayische Acari. Treubia 8: 106. 



Poecilochiridae Willmann, 1940 

Figure 42 



Diagnosis: The family is character- 
ized by Willmann on the basis of the 
males and deutonymphs as follows: 
the male genital opening is in a spe- 
cial presternal plate; in other re- 
spects it is similar to Parasitus, (leg 
II of the males has well-developed 
apophyses). Deutonymphs are 
strongly heteromorphic, with very 
long legs and exceptionally long, 
stiff setae. Cheliceral chelae are 
present with an anterior, projecting, 
leaflike process. The sternal plate 
usually has a dark, transverse band. 
Neumann reports that the females 
are similar to the Parasitidae. 




Figure 42 Poecilochinis iiecrophori 
Vitzthum, 1930. Sternal plate of 
deutonymph. (After Cooreman 
1943) 



Genus: 

Poecilochinis G. and R. Canestrini, 1882 

Type. Poecilochirus carabi G. and R. Canestrini, 1882 

Discussion: Poecilochirids are found associated with beetles and in 
caves or burrows inhabited by beetles. Species have been reported 
from Europe and Asia. They are not known to be of any medical or 
economic importance. 



58 Acarology 

References: 

Neumann, K. W. 1943. Die Lebengeschicte der Kafermilbe Poecilochinis 

necrophi Vitzthum, nebst Beschreiberung aller Entwicklungstufen. 

Zool. Anz. 142:1-21. 
Vitzthum, H. G. 1930. Milben als Pesttrager? Zool. Jahrb. Syst. 60:381- 

428. 
Willmann, C. 1940. Neue Milben aus Hohlen der Balkanhablinsel, gesam- 

melt von Prof. Dr. K. Absolon, Briinn. Zool. Anz. 130:209-218. 



Aceosejidae N.F. 

Figure 43 

LAr'7^v^^?<<.<c^ Diagnosis: The females can be 

-j<^^^^^^^^^\ recognized because they possess 

^^^^^^^^^^^^^U jugular plates. In other words the 

M^r^^^^ W anterior sternal plate i is sepa- 

rated from the other sternal plates 

Figure 43 Aceoseiiis miiricatiis and is further Split into tWO SO 

1 A?.'^^c u^\ Vo^ 1?^ ^'^^ ""^ "'^^^- that one half lies on either side of 
(After Sellnick 1941) 

the tritosternum. Sternal setae i 
are on these plates. The epigynial plate bears a single pair of setae. 
Posterior to the epigynial plate there is a large ventroanal plate. The 
male is unique in that the ventroanal plate is provided with a cone- 
shaped elevation that bears a pair of genital suckers. All legs are 
provided with pretarsi, caruncles, and claws. 

Genus: 

Aceosejus Sellnick, 1941 

Type. Sejus muricatus Koch, 1839 

Discussion: Only the type species is recognized as belonging to this 
family. The splitting of the sternal plate in the female and the presence 
of suckers on a cone of the ventroanal plate of the male are such pe- 
culiar features that a new family had to be erected to accommodate 
this genus. These mites live in rotting wood and are ol no known eco- 
nomic or medical importance. 

Reference: 

Sellnick, M. 1941. Einige Milbenarten C. L. Kochs. Zool. Anz. 133:146- 
155. 



Mesostigmata 



59 



Rhodacaridae Oudemans, 1902 

Figure 44 

Diagnosis: The following diagnosis is taken from 
Vitzthum 1941. The rhodacarids are colorless, gold- 
en, or rose-red mites that are from 0.3 to 0.5 mm. 
in length. They are elongated, and the length is usu- 
ally three times as great as the width. The opistho- 
soma is separated by a deep furrow from the 
podosoma and some movement between the opistho- 
soma and podosoma is possible. A dividing line may 
also separate the propodosoma from the metapodo- 
soma. The sternal plate projects anteriorly so that 
it covers the male genital opening. Tarsi ii, iii, and 
IV have pretarsus, caruncle, and claws. Tarsus i 
either lacks an ambulacral apparatus or the pretarsus 
and claws are vestigial. The anterior margin of the 
tectum is attenuated into three-toothed points. The 
middle element is usually much longer than the 
lateral ones. 




Figure 44 

Rhodacarus 
roseiis Oude- 
mans, 1910. 
Ventral view of 
male. (After 
Banks 1915) 



Genera: 



1. Rhodacarus Oudemans, 1902 

Type. Rhodacarus roseus Oudemans, 1902 

2. Rhodacaropsis Willmann, 1935 

Type. Rhodacaropsis inexpectatus Willmann, 

3. Rhodacarellus ^'\\\m?inti, \93>5 

Type. Rhodacarellus subterraneus Willmann, 



1935 



1935 



Discussion: Rhodacarids are frequently found in material collected 
from litter. The family has not been well studied and many species 
await description. They are of no known medical or economic impor- 
tance. 



Reference: 

Willmann, C. 1935. III. Ueber eine eigenartige Milbenfauna im Klisten- 
grundwasser der Kielen Bucht. Schr. naturw. Ver. Schl.-Holst. 20: 

422-434. 



60 



Acarology 



Ixodorhynchidae Ewing, 1923 

Figure 45 

Diagnosis: Ixodorhynchids are readily recognized by their harpoon- 
shaped anterior lateral extensions of the pedipalpal coxae in the 
females, protonymphs, and deutonymphs. These stages also have a 
peculiar chelicera that lacks a fixed digit and has large, recurved teeth 
on the movable digit. Larvae and tritonymphs have not been ob- 
served and in fact may not exist. The males lack both of the features 
so characteristic of the other stages. They can be recognized, however, 
because even though the harpoon blade is lacking on the anterior, lat- 
eral processes of the pedipalps 
the basal portion of these 
processes are similar to those 
of the other stages. Chelicerae 
of males are chelate and modi- 
fied for transferring sperma- 
tophores. 

Figure 45 Ixodorhynchus 
hiitantanensis (Fonseca), 1934. 
Ventral view of female 
and gnathosoma. (After 
Fonseca 1934) 





Genus: 

Ixodorhynchus Ewing, 1923 (= Ixobioides Fonseca, 1934) 
Type. Ixodorhynchus liponyssoides Ewing, 1923 

Discussion: These peculiar mites have been found only as parasites 
of snakes. The type species was collected from the eye of a snake at 
Madrid, Iowa. The only other species, /. butantanensis (Fonseca), 
1934 was collected from a snake Optis merremi Wagler, 1824, from 
Brazil. These mites are of no known economic or medical importance, 



References: 

Ewing, H. E. 1923. The dermanyssid mites of North America. Proc. U. S. 

Nat. Mus. 62 Art. 13:1-26. 
Fonseca, F. da. 1934. Der Schlangenparasit Ixobioides novi generis n. sp. 

(Acarina, Ixodorhynchidae nov. fam.) Zeit. Parasitenk. 6:508-527. 



Mesostigmata 



61 



Spelaeorhynchidae Oudemans, 1902 

Figure 46 

Diagnosis: Spelaeorhynchids can be readily recognized by the pecul- 
iar arrangement of the tectum and the attachment of the cheHcerae 
and palps. The tectum surrounds a broad opening (camerostome) in 
the idiosoma, into which the chelicerae may be withdrawn. The stig- 
mata are small and are situated 
lateral to the space between 
coxae III and iv. The median 
hypostome is stylet-shaped. 
Chelicerae are large and termi- 
nate in two large hooks. The 
dorsal plate covers only the 
podosoma and the posterior 
dorsal surface of the body is not 
sclerotized. Dorsally the tectum 
has a broad connection with 
the dorsal plate. 

Figure 46 Ventral view of Spelae- 
orhynchus sp. 




Genus: 

Spelaeorhynchus Neumann, 1902 

Type. Spelaeorhynchus proecursor Neumann, 1902 

Discussion: Spelaeorhynchids are parasitic on Central and South 
American bats. They are aberrant in that they do not conform to or 
show very close affinities with any of the mites. That they properly 
belong to the Mesostigmata is beyond question, although Banks and 
Neumann held that they were closely related to the ticks. They are 
placed in the Gamasides following the lead of Vitzthum 1941. These 
mites are not known to be of any medical or economic importance. 



Rejerence: 

Neumann, G. 1902. Spelaeorhynchus praecursor n. g. n. sp., nouvel acarien 
parasite. Arch, de Parasitol. 5:31-37. 



62 



Acarology 



Spinturnicidae Oudemans, 1901 

Figures 47, 48 

Diagnosis: Spinturnicids are brown, medium-sized mites from 0.5 to 
1 mm. long. They are usually flat, and in Periglischriis (Figure 48) 
the opisthosoma has lateral expansions. The dorsal plate is entire or 




Figure 41 Spinturnix carloshoffmanni Hoffmann, 1944. Dorsal and ventral 
views of female. (After Hoffmann 1944) 

divided into two. The legs are relatively long but very stout. All of the 
coxae are immovable and arranged radially. The tarsi are provided 
with short pretarsi, large caruncles, and strong claws. The tritoster- 
num is reduced to a delicate plate or is replaced by a relatively large 




Figure 48 Periglischriis vargasi Hoffmann, 1944. Dorsal and ventral views of 
female. (After Hoffmann 1944) 



Mesostigmata 63 

praeendopodal plate. The anal opening is subterminal or terminal on 
a small projection. The peritremes and stigmata are frequently dorsal 
rather than ventral. 

Genera: 

1. Spinturnix v. Heyden, 1826 (= Pteroptus Dufour, 1832 and Diplo- 
staspis Kolenati, 1857) 

Type. Spinturnix myoti Kolenati, 1856 (see Opinion 128 of the Inter- 
national Commission on Zoological Nomenclature) 

2. Ancystropus Kolenati 1856 (= Leiostaspis Kolenati, 1857) 
Type. Ancystropus zeleborii Kolenati, 1856 

3. Meristaspis Kolenati, 1857 

Type. Meristaspis lateralis Kolenati, 1857 

4. Periglischrus Kolenati, 1857 

Type. Periglischrus caligus Kolenati, 1857 

5. Tympanospinctus Berlese, 1918 

Type. Tympanospinctus paradoxus BqyXqsq, 1918 

Discussion: Spinturnicids have been found almost exclusively on bats. 
The one exception, Tympanospinctus paradoxus, v^as found on Cras- 
sarchus jasciatus. It is impossible to tell from Berlese's description 
whether or not T. paradoxus is in reality a spintumicid, but since he 
assigned it to this family it probably is. Species of the family have 
been found on bats all over the world. The genus Spinturnix gives 
birth to living young. The family is not known to be of any medical 
or economic importance. 

References: 

Hirst, S. 1927. Note on Acari, mainly belonging to the genus Spinturnix 
von Heyden. Proc. Zool. Soc. London. Ft. 11:323-338. 

Vitzthum, H. G. 1931. Neue parasitische Fledermaus-milben aus Vene- 
zuela Ziet. f. Parasitenk. 4:1-47. 

Ascaidae Oudemans, 1905 

Figure 49 

Diagnosis: Ascaids are distinguished bv -the presence of a bifurca te 
seta at the base of t he palpal tarsus and a dorsal plate that is divided 
i nto an anterior and po stprior sert ion of a p2I oximately_ec iuaLdimen- 
sions. The tarsi of all legs have pretarsi, caruncles, and claws. The 
female genital plate is truncated or rounded anteriorly and is sepa- 



64 Acarology 

rated by a straight or slightly curved line from the ventroanal plate. 

(Vitzthum 1941 follows Oudemans 1939 in the use of the familial 

name Allolaelaptidae. Such a 
course is contrary to the practice 
of forming familial names and is 
not followed here.) 




Figure 49 Asca qumquesetosa Whar- 
ton, 1941. Ventral view of female. 
(After Wharton 1941) 



Genera: 

1. Asca V. Heyden, 1826 

Type. Acarus ophidioides Linnaeus, 1758 

2. Cyrtolaelaps Berlese 1887 (= Protolaelaps Traghardh, 1912, non 

Cyrtolaelaps Berlese, 1892) 
Type. Gamasus mucronatus G. and R. Canestrini, 1881 
(r= Gamasellus brevispinosus Tragardh, 1910 
= Asca affinis Oudemans, 1902) 

3. Dendrolaelaps Halbert, 1915 

Type. Dendrolaelaps oudemansi Halbert, 1915 

4. Gamasellus Berlese, 1892 

Type. Gamasus falciger G. and R. Canestrini, 1882 

5. Laelogamasus Berlese, 1904 

Type. Gamasus {Laelogamasus) simplex Berlese, 1904 

6. Lobocephalus Kramer, 1898 

Type. Lobocephalus acuminatus Kramer, 1898 (poorly described, 
position uncertain) 

Discussion: Ascaids are characteristically found in litter and other 
accumulations of organic debris. They are fairly common, but little 
information is available on their life cycle or habits. Wharton 1941 
found specimens in debris from a boobie's nest, while Fox 1947 re- 
ports a specimen from a rat in Puerto Rico. The record of Fox should 
not be taken as demonstrating parasitism in this group. The chelicerae 



Mesostigmata 



65 



are large and strongly toothed in the fashion of predaceous species. 
Ascaids are not known to be of any medical or economic importance. 

References: 

Oudemans, A. C. 1939. Neue Funde auf dem Gebiete der Systematik und 
der Nomenclatur der Acari. III. Zool. Anz. 126:20-24. 

Wharton, G. W. 1941. Acarina collected on the presidential cruise of 1938. 
Smithsonian Miscellaneous Collections. 99. No. 12:1-8. 



Veigaiaidae Oudemans, 1939 

Figure 50 

Diagnosis: Veigaiaids may be 
recognized not only by the four 
tines of the forked seta on the 
palpal tarsus but also by the pe- 
culiar shape of the tectum. The 
tectum has two small, lateral, 
toothed processes and a long, 
thin, median projection that may 
or may not bear terminal teeth on 
its slight anterior expansion. The 
dorsal plate is divided into two 
either completely or partially. 
Partial division results when the 
fissure between the plates does 
not reach the midline. The epi- 
gynial plate of the female is sig- 
nificantly sclerotized only be- 
tween coxae IV. The plate, 
however, is extensive and has a thin anterior margin. Sclerotized 
structures are present in the walls of the vagina. The male has apoph- 
yses on leg II and a well-developed extension of the movable digit 
for use in copulation. 




Figure 30 Veigaia transisalae (Oude- 
mans), 1901. Ventral view of female. 
(After Willmann 1936) 



Genera: 



Veigaia Oudemans, 1905 (= Cyrtolaelaps Berlese, 1892 non Berlese, 

1887) 
Type. Gamasus uemorensis Koch, 1836 
Cyrthydrolaekips Berlese, 1904 
Type. Cyrthydrolaekips hirtus Berlese, 1904 



66 



Acarology 



Discussion: Little is known concerning the biology of these mites. 
Willmann reports them from numerous caves, but others have been 
found on the surface. They are of no economic or medical importance 
as far as is now known. 

References: 

Berlese, A. 1904. Acari nuovi. Redia 2:10-32. 

Willmann, C. 1936. Mitteleuropaische Arten der Gattung Veigaia (Para- 
sitidae, Acari). Zool. Anz. 116:249-258. 




Figure 51 Perga- 
masiis probsti 
Oudemans, 1912. 
Ventral view of 
female. (After 
Vitzthum 1940) 



Parasitidae Oudemans, 1901 

Figure 51 

Diagnosis: The females of the family Parasitidae 
can be easily recognized because they have a pair 
of large, metasternal plates flanking the epigynial 
plate. The males usually have exceptionally large 
apophyses on leg ii but other famihes also have 
similar males. Tarsi of all legs are provided with 
a pretarsus, caruncle, and claws. The forked seta 
on the palpal tarsus has three tines. In the males, 
the movable digit of the chelicera is greatly modi- 
fied for copulation. The dorsal plate is entire or, 
more usually, divided into two. The tectum is 
basically tridentate. The ventral plates have vari- 
ous arrangements, but the epigynial plate is always 
triangular with a posterior base and anterior apex. 
Sclerotized structures are present in the vaginal 
wall. 



Genera: 

1. Parasitiis Latreille, 1795 (= Carpais Latreille, 1796 

= Gamasus Latreille, 1802) 
Type. Acarus fucorum DeGeer, 1778 

2. A mbly gamasus Berlese, 1903 

Type. Gamasus tiberinus G. and R. Canestrini, 1882 

3. Eugamasus Berlese, 1893 

Type. Gamasus magnus Kramer, 1876 

4. Holoparasitus Oudemans, 1936 
Type. Gamasus calcaratus Koch, 1839 



Mesostigmata 67 

5. Nemnichia Oudemans, 1936 

Type. Zercon eleganiulits Koch, 1839 (incomplete information, posi- 
tion doubtful) 

6. Oocarpais Berlese, 1916 

Type. Oocarpais donisthorpei Berlese, 1916 

7. Parasitellus WiWmdinn, \9?>9 

Type. Eugamasus ferox Tragardh, 1910 

8. Pergamasus Berlese, 1903 

Type. A cams crassipes Linnaeus, 1758 

9. Trachygamasiis Berlese, 1906 

Type. Gamasus pusillus Berlese, 1892 

Discussion: Parasitid mites are found typically in accumulations of 
organic material such as rotting logs and litter. They are of no known 
economic or medical importance. However, since they are predaceous 
they probably aid in the destruction of many small insects. 

References: 

Berlese, A. 1905. Monografia del genere Gamasus Latr. Redia 3:66-304 

+ 18 PI. 
Oudemans, A. C. 1939. Neue Funde auf dem Gebeite der Systematik und 
der Nomenklatur der Acari. IV. Zool. Anz. 126:195-201. 

Macrochelidae Vitzthum, 1930 

Figure 52 

Diagnosis: The elongated, usually clawless leg i of macrochelids will 
distinguish them from other gamasids. The ventral plates of the fe- 
males are also diagnostic. The sternal plate bears three setae and two 
pores. The metasternal plates are minute and not fused with endopodal 
plates. Each metapodal plate bears a seta and a pore at its anterior 
border. The epigynial plate is truncate anteriorly and posteriorly; it 
bears a single pair of setae. The ventral plate is fused with the anal 
plate and may be considerably reduced. The tectum consists of a me- 
dian, narrow, branched or toothed element that may or may not be 
flanked by smaller lateral elements. The dorsal plate is usually entire. 

Genera and subgenera: 

1. Macrocheles Latreille, 1829 
a. Machrocheles s. str. 

Type. Acariis muscae Scopoli, 1772 (= Acarus marginatus Her- 
mann, 1804) 



68 



Acarology 



b. Coprholaspis Berlese, 1918 

Type. Holostaspis glabra MiJller, 1859 (= Gamasus stercorarius 
Kramer, 1876) 

c. Gamasholaspis Berlese, 1903 

Type. Gamasholaspis gamasoides Berlese, 1903 

d. GeholaspisBQvXc^Q, 1918 

Type. Gamasus longispinosus Kramer, 1878 

e. Holaspuliis Berlese, 1903 

Type. Holostaspsis (Holaspiilus) teniiipes Berlese, 1903 

f. Nothroholaspis Berlese, 1903 

Type. Holostaspis tridentimis G. and R. Canestrini, 1882 



^^ 




Figure 52 Macrocheles coprophila 
Womersley, 1942. Ventral view of 
female. (After Womersley 1942) 



2. Calholaspis Berlese, 191: 
Type. Calholaspis siiperbus Berlese, 1918 

3. Ewep/crm^ Womersley, 1942 

Type. Euepicriiis filamentosus Womersley, 1942 

4. Holocelaeno Berlese, 1910 

a. Holocelaeno s. str. 

Type. Holocelaeno mitis Berlese, 1910 

b. Euholocelaeno Berlese, 1918 

Type. Holocelaeno bursiformes Berlese, 1910 

5. Holostaspella Berlese, 1903 
a. Holostaspella s. str. 

Type. Holostaspis {Holostaspella) sciilpta Berlese, 1903 



Mesostigmata 69 

b. Prholaspina Berlese, 1918 

Type. Holostaspella micrarhena Berlese, 1916 

c. Tricholocelaeno Berlese, 1918 

Type. Holocelaeno longicoma Berlese, 1910 

6. Mflcro/fl5/?/5 Oudemans, 1931 
Type. Gamcisus opaciis Koch, 1839 

7. Neopodocinum Oudemans, 1902 

Type. Neopodocinum jaspersi Oudemans, 1902 

8. Parholaspis "QqtXqsq, \9\^ 

Type. Parholaspis desertus Berlese, 1918 

9. TrigonholaspisWXzihuxn, 1930 

Type. Trigonholaspis salti Vitzthum, 1930 

Discussion: Macrochelids are extremely common and are found in 
the soil, on invertebrates, and on vertebrates. Although they are regu- 
larly associated with various hosts they are probably not parasitic in 
the usual sense. Pereira and de Castro 1945, however, have found that 
there is reason for the association in at least one case. Macrochcles 
muscae (Scopoli), 1772 was found to feed in all instars but the first 
(that does not feed) on the eggs of the housefly. Such a habit indicates 
that macrochelids may have considerable economic as well as medical 
importance although as yet the group has not been well investigated 
from this aspect. 

References: 

Cooreman, J. 1943. Note sur la faune des Hautes-Fagnes en Belgique. Bull. 

Mus. Roy. Hist. Natur. Belgique. 19, No. 63:1-28. 
Pereira, C. and M. P. de Castro. 1945. Contribuicoo para o conhecimento 

da especie tipo de "Macrocheles Latr." ("Acarina") : "M. muscae- 

domesticae (Scopoli, 1772)" emend. Arquivos Inst. Biol. 16:153-186. 
Oudemans, A. C. 1931. Acarologishe Aanteekenigen. CVII. Ent. Ber. 

8:272-273. 
Vitzthum, H. G. 1926. Malayische Acari. Treubia. 8, Linn. 1-2:1-198. 

Pachylaelaptidae Vitzthum, 1931 

Figure 53 

Diagnosis: The ventral armature of the female will distinguish pachy- 
laelaptids from most other gamasids. The parapodal, peritremal, and 
metapodal plates are fused into one and extend posterior to coxae iv. 
They may actually abut the ventral plate and with it cover the major 



70 



Acarology 



portion of the ventral surface posterior to the coxae. The forked seta 
on the palpal tarsus has three tines. All tarsi are provided with pretarsi. 




Figure 53 Pachylaelaps roosevelti 
(Wharton), 1941. Ventral view of 
female. (After Wharton 1941) 



Genera and subgenera: 

1. Pachylaelaps Berlese, 1886 

a. Pachylaelaps s. str. 

Type. Gamasus pectinifer G. and R. Canestrini, 1881 

b. Brachylaelaps Berlese, 1910 

Type. Pachylaelaps {Brachylaelaps) rotundus Berlese, 1910 

c. Elaphrolaelaps Berlese, 1910 

Type, Pachylaelaps {Elaphrolaelaps) fenestratus Berlese, 1910 

d. Olopachys Berlese, 1910 

Type. Pachylaelaps {Olopachys) scutatus Berlese, 1910 

e. Onchodellus Berlese, 1904 

Type. Pachylaelaps {Onchodellus) reticulatus Berlese, 1904 

f. Paralaelaps Tragardh, 1908 

Type. Paralaelaps kibonotensis Tragardh, 1908 

g. Platylaelaps Berlese, 1905 

Type. Pachylaelaps {Platylaelaps) latus Berlese, 1905 

2. Coprolaelaps Berlese, 1908 

Type. Coprolaelaps caputmedusae Berlese, 1908 

3. Megalolaelaps Berlese, 1892 

Type. Pachylaelaps haeros Berlese, 1888 

4. Pachylaella Berlese, 1916 

Type. Pachylaella robustissma Berlese, 1896 

5. Sphaerolaelaps Berlese, 1903 

Type. Laelaps holothyroides Leonard!, 1896 

Discussion: Pachylaelaptids are found in accumulations of organic 



Mesostigmata 71 

debris or on insects, especially beetles. They are of no known economic 
or medical importance. 

References: 

Berlese, A. 1910. Lista di nuove specie e nuovi generi di Acari. Redia 

6:242-271. 
Vitzthum, H. G. 1931. Resultats scientifiques du voyage aux Indes Orien- 

tales Neerlandaises de LL. AA. Belgique. Acarinen. Mem. Mus. Hist. 

Nat. Belgique. (Hors. Serie) 3, Fasc. 5:1-55. 




Gamasolaelaptidae Oudemans, 1939 

Figure 54 

Diagnosis: Gamasolaelaptids are recognized by 
t heir divided dorsal plates and the rounded anterio r 
mar gin, of the heavilv sclerotized portion of th e 
epigynial plate . All legs are provided with caruncles 
and claws . The forked seta on the palpal tarsus ha s 
three tines . The tectum has a single, long, median, 
anterior projection in at least some species. 



Figure 54 Digamaselliis frenzeli Willmann, 1936. Ventral 
view of female. (After Willmann 1936) 



Genera: 



Gamasolaelaps Berlese, 1 903 ( = Metaparasitus Oudemans and 

Voigts, 1904) 

Type. Cyrtolaelaps aurantiacus Berlese, 1903 

{— Metaparasitus soholes Oudemans and Voigts, 1904) 
Digamasellus Berlese, 1905 

Type. Gamasellus {Digamasellus) perpusillus Berlese, 1905 
Euryparasitus Oudemans, 1901 
Type. Gamasus emarginata Koch, 1839 
Halolaelaps Berlese and Trouessart, 1889 
Type. Gamasus marinus Brady, 1875 (= Halolaelaps glubrinsculus 

Berlese and Trouessart, 1889 



72 Acarology 

5. Gamasodes Oudemans, 1939 

Type. Gamasodes spiniger Oudemans, 1936 (= Gamasus spinipes 
Koch, 1841, non Gamasus spinipes Say, 1821) 

6. Saintdidieria Oudemans, 1939 ^ 
Type. Parasitus sexclavatiis Oudemans, 1902 

Discussion: Gamasolaelaptids live in damp soil or moss where they 
probably prey on other small arthropods or their eggs. Saintdidieria 
sexclavatiis was associated with psoroptid mites of horses. They are of 
no known medical or economic importance. 

References: 

Oudemans, A. C. 1939. Neue Funde auf dem Gebiete der Systematik und 
der Nomenklatur der Acari. IV. Zool. Anz. 126:195-201. 

Womersley, H. 1942. Additions to the Acarina — Parasitoidea of Australia. 
Trans. Roy. Soc. South Australia. 66:142-171. 



Neoparasitidae Oudemans, 1939 

Figure 55 




Diagnosis: Neoparasitids are sim- 
ilar to the gamasolaelaptids but 
are readily separated from them 
because they have an entire dor- 
sal plate rather than one divided 
into anterior and posterior sec- 
tions. The epigynial plate is not 
triangular and possesses a mem- 
branous anterior margin that may 
be thrown into folds. All legs 
are provided with caruncles and 
claws. The specialized seta on the 
palpal tarsus has three tines. 



Figure 55 Neoparasitiis oudemansi 
(Oudemans), 1901. Ventral view of 
female. (After Vitzthum 1926) 



Mesostigmata 73 

Genera and subgenera: 

1. Neoparasitus Oudemans, 1901 (= Pachyseiiis Berlese 1910) 
Type, Neoparasitus oudemansi Oudemans, 1901 

{— Pachyseius quartiis Vitzthum, 1926) 

2. Austrogamasiis Womersley, 1942 

Type. Cyrtolaelaps gracilipes Banks, 1916 

3. Beaurieina Oudemans, 1929 

Type. Neopodochnim nederv eeni 0\x6Qm?Lns, 1903 (= Megalolaelaps 
spinirostris Berlese, 1910) 

4. Donia Oudemans, 1939 

Type. Hypoaspis gehennalis Oudemans, 1916 

5. Epicriopsis Berlese, 1916 

a. Epicriopsis s. str. 

Type. Gamasus horridus Kramer, 1876 

b. Actinoseius Berlese, 1916 

Type. Actinoseius terrificus Berlese, 1916 

6. Epiphis Berlese, 1916 

Type. Gamasiphis {Epiphis) rarior Berlese, 1916 

7. Gamasiphis Berlese, 1903 

Type. Gamasus pulchellus Berlese, 1887 

8. Hydrogamasus Berlese, 1892 

Type. Gamasus salinus Laboulbene, 1851 (= Gamasus littoralis G. 
and R. Canestrini, 1881) 

9. MegaliphisW\\\mdinn,\9?>d> 

Type. Gamasiphis (Megaliphis) giganteus Willmann, 1938 

10. Ologamasus Berlese, 1888 (= Ologamasellus Berlese, 1914) 

a. Ologamasus s. str. 

Type. Gamasus aberrans Berlese, 1888 

b. Micriphis Berlese, 1914 

Type. Gamasiphis gamasellus Berlese, 1913 

11. Pm/?/zw Berlese, 1914 

Type. Eumaeus hemisphaericus Koch, 1842 

12. SphaeroseiusBQvlQSQ, \90A 

Type. Laelaps ecitonis Wasmann, 1901 

Discussion: Neoparasitids are found in soil, moss, and decaying or- 
ganic material. They are of no known economic or medical importance. 

References: 

Vitzthum, H. G. 1926. Malayische Acari. Treubia. 8:1-198. 
Womersley, H. 1942. Additions to the Acarina — Parasitoidea of Australia. 
Trans. Roy. Soc. South Australia. 66:142-171. 



74 



Acarology 



Pseudoparasitidae Vitzthum, 1941 

Figure 56 

Diagnosis: Pseudoparasitids have much in common with the preced- 
ing two famihes but they may be recognized by the reduction of the 
pretarsus and caruncle of leg i and the modification of the claws of 
this appendage. The epigynial plate is not triangular. It may or may 

not be fused with the ventral 
plate. The dorsal plate is entire al- 
though there may be a suggestion 
of a horizontal suture present. 
The specialized seta on the palpal 
tarsus has three tines. 



Figure 56 Leptogamasus suecicus 
Tragardh, 1936. Tarsus i of female 
showing modified claws and caruncle 
and ventral plates of female. The claws 
of leg I of the male are not modified. 
(After Tragardh 1936) 





Genera and subgenera: 

1. Pseiidoparasitus Oudemans, 1902 (= Hoplolaelaps Berlese, 1903 but 

not 1910) 

a. Pseudoparasitus s. str. 

Type. Laelaps meridionalis G. and R. Canestrini, 1882 

b. Alloparasitus Berlese, 1920 

Type. Pseudoparasitus angulatus Berlese, 1916 

c. Praeparasitus Berlese, 1920 

Type. Pseudoparasitus {Praeparasitus) coUaris Berlese, 1920 

d. Pseudopachys Berlese, 1916 

Type. Pseudoparasitus {Pseudopachys) parasitizans Berlese, 1916 

2. Leptogamasus Tragardh, 1936 

Type. Leptogamasus suecicus Tragardh, 1936 

3. Sessiluncus G. Canestrini, 1898 

Type. Gamasus heterotarsus G. Canestrini, 1897 

Discussion: The Gamasolaelaptidae, Neoparasitidae, and Pseudo- 
parasitidae are poorly known and the number of undescribed species 



Mesostigmata 



75 



in these families is extremely large. Most of the gamasid mites found 
in soil, moss, or organic debris belong to one of these three families. 
It is probable that additional knowledge will reveal that a realignment 
of the genera will be desirable. Pseudoparasitids are not known to be 
of any economic or medical importance. 

References: 

Tragardh, I. 1936. Leptogamasus, a new genus of Acari from Sweden. 

Ent. Tidsk. 1936:228-234. 
Vitzthum, H. G. 1926. Malayische Acari. Treubia. 8:1-198. 



Raillietidae Vitzthum, 1941 

Figure 57 



Diagnosis: Females can be recog- 
nized by the reduction or absence of 
the basal portion of the tritosternum, 
a fairly well sclerotized epigynial 
plate, and an oval shape. Males have 
apophyses on leg ii and thus differ 
from other males that have a two- 
tined, specialized seta on the palpal 
tarsus. The dorsal plate in both 
sexes is undivided. All legs possess 
pretarsi, caruncles, and claws. They 
are parasites in the external auditory 
meatus of cattle and antelopes. 

Genus: 




Figure 51 Raillietia aiiris (Leidy), 
1872. Ventral view of female. 
(After Hirst 1922) 



Raillietia Trouessart, 1902 
Type. Gamasiis auris Leidy, 1872 

Discussion: Only two species have been described in this family: 
Raillietia auris Leidy, 1872; and Raillietia hopkinsi Radford, 1938. 
According to Hirst 1922, R. auris is present in North America and 
Europe and in some places is rather common. R. auris is reported to 
gain its nourishment from the wax and sloughed epidermal cells. It 
probably does not suck blood. R. hopkinsi was found in the ears of 
the antelope Kobus dejassa ugandae Neumann where it probably lives 
a life similar to R. auris from cattle. No pathology is associated with 



76 



Acarology 



infestation by raillietids. R. amis passes the larval stage within the egg 
and nymphs or eggs containing nymphs are liberated by the females. 

Rejerences: 

Hirst, S. 1922. Mites injurious to domestic animals. Brit. Mus. (Nat. Hist.) 

Econ. Ser. 13:1-107. 
Radford, C. D. 1938. Notes on some new species of parasitic mites. Para- 

sitol. 30:427-440. 



Halarachnidae Oudemans, 1906 

Figure 58 

Diagnosis: Halarachnids are endoparasites in the respiratory passages 
of mammals. They appear to represent an extreme modification of the 
laelaptid mites. Their body shape varies from oval {Pneumonyssus) 
to wormlike {Orthohalarachne attenuata) . The dorsal plate is reduced 




Figure 58 Pneumonyssus simicola Banks, 1901. Ventral view of male (right), 
female (left), and dorsal view of female (center). (After Vitzthum 1931) 

and undivided, the tritosternum is absent, and the sternal plate is re- 
duced. Only three pairs of sternal setae are present. The genital plate 
of female is rudimentary, while the male genital opening is in the 
anterior margin of the sternal plate. The anal opening is posterior on 
an anal plate that bears three or four setae. Stigmata with small peri- 
tremes lateral to the region of coxae iv are present. The tectum is 
simple and triangular, while the hypostome is triangular and pilose. 
Chelicerae with the movable digit more strongly developed than the 
fixed digit are present. The palps have four segments. Forked hair 



Mesostigmata 77 

which has two tines is present on the palpal tarsus. All legs are pro- 
vided with pretarsi, caruncles, and claws. 

Genera: 

1. Halarachne Allman, 1847 

Type. Halarachne halichoeri AWmsin, 1847 (= Rhinixodes l^ehring, 
1884 and Rhinacarus Nehring, 1884) 

2. Pneumonyssus Banks, 1901 {— Pneumotuber Landois and Hoepke, 

1914) 
Type. Pneumonyssus simicola Banks, 1901 

3. Orthohalarachne Newell, 1947 

Type. Halarachne attenuata Banks, 1910 

Discussion: Newell 1947 has given an excellent account of the mor- 
phology and systematics of this family. His paper forms the basis for 
most of the following discussion, although other authors have been 
consulted. 

Halarachnids live in the air passages of mammals. Their life cycles 
are unknown but a few pertinent facts concerning their biology have 
been observed. Doetschman 1944 and others have found the six-legged 
larvae associated with the adult males and females. No nymphs be- 
longing to this family have been seen. It should, however, be kept in 
mind that the life history has not yet been observed in its entirety and 
the methods by which new hosts are invaded have not yet been deter- 
mined. The genus Halarachne is found exclusively in the respiratory 
passages of seals of the family Phocidae, the Orthohalarachne para- 
sitize the other families of the Pinnipedia, and Pneumonyssus is found 
in apes, dogs, and other mammals. 

Although infection with species of Pneumonyssus is fairly common 
in some primates, no human infections have been discovered. Human 
pulmonary acariasis is a common ailment in some areas such as parts 
of India, and during World War II the syndrome produced by infec- 
tion of human respiratory passages with mites was known as Tropical 
Eosinophilia. The mites that were recovered were not halarachnids, 
but common, free-living species. 

References: 

Carter, Henry F. and V. St. E. D'Abrera. 1946. Mites (Acarina) — a prob- 
able factor in the aetiology of spasmodic bronchitis and asthma asso- 
ciated with high eosinophilia. Trans. Roy. Soc. Trop. Med. & Hyg. 
39:373-395. 



78 



Acarology 



Chandler, W. L. and D. S. Ruhe. 1940. Pneumonyssus caninum n. sp., a 

mite from the frontal sinus of the dog. J. Parasitol. 26(1) : 59-70. 
Doetschman, Willis H. 1944. A new species of endoparasitic mite of the 

family Halarachnidae (Acarina). Trans. Amer. Micro. Soc. 63:68- 

72. 
Newell, Irwin M. 1947. Studies on the morphology and systematics of the 

family Halarachnidae Oudemans 1906 (Acari, Parasitoidea). Bull. 

Bingham. Oceanogr. Coll. 10(4) :235-266. 
Vitzthum, H. G. 1931. Pneumonyssus simicola Banks. Z. Parasitenk. 4: 

48-74. 

Entonyssidae Ewing, 1923 

Figure 59 

Diagnosis: Entonyssids are parasitic in the lungs of snakes. They are 
oval in shape and may reach 1 mm. in length. The tritosternum is rudi- 
mentary in the female and according to Radford 1937 is absent in both 
males and females of E. bedfordi Radford, 1937. The dorsal plate is 





Figure 59 Entonyssus glasmacheri 
Vitzthum, 1935. Dorsal and ventral 
views of female. (After Vitzthum 
1935) 



undivided and usually reaches the posterior margin. If the plate is 
restricted to the propodosoma there will be two strong setae on its 
posterior margin. All legs are provided with pretarsi, caruncles, and 
claws. The chelicerae lack well-developed teeth. The forked seta on 
the palpal tarsus bears two tines. 

The following key to the subfamilies is taken from Turk 1947, who 
considers them to be of familial rank. 



Key to the Entonyssidae 

Chelae with movable digit falciform and fixed digit harpoon-like 
with retrograde tooth or with both digits falciform generally with- 
out setae Entonyssinae 

Chelae of female with weakly sclerotized, long movable digit that 
is strongly recurved laterally and lacks teeth and setae; fixed digit 
reduced Pneumophionyssinae 



Genera: 



Mesostigmata 79 

Entonyssinae Ewing, 1923 



1. Entonyssus Ewing, 1923 

Type. Entonyssus halli Ewing, 1923 

2. Hammertonia Turk, 1947 

Type. Entonyssus bedfordi Radford, 1937 

3. Ophiopneumicola Hubbard, 1938 

Type. Ophiopneumicola colubri Hubbard, 1938 

Pneumophionyssinae Turk, 1947 
Genus: 

Pneumophionyssus Fonseca, 1940 

Type. Pneumophionyssus aristoterisi Fonseca, 1940 

Discussion: Entonyssids have been found only in the respiratory 
passages of snakes. Their life history has not yet been completely elu- 
cidated, but it is probably considerably foreshortened. Fully developed 
larvae have been seen in the females so the assumption that they are 
ovoviviparous is well founded. Radford 1937 is the only author who 
reports finding nymphs of this family. Turk 1947 suggests that Rad- 
ford's observations may have been inaccurate and that the larvae molt 
directly into the adult males and females. Since no one has followed 
the complete cycle of any species the question must remain open. En-, 
tonyssids have been found in America and Africa. There is no reason 
to suppose that they will not eventually be found in other locahties. 
As far as is known these mites cause their hosts little discomfort. They 
are not known to be of any economic or medical importance. 

References: 

Radford, C. D. 1937. A new species of mite of the genus Entonyssus 
Ewing. The North Western Naturalist. Mar. 1937:38-42. 

Turk, F. A. 1947. Studies of Acari IV. A review of the lung mites of 
snakes. Parasitol. 38:17-26. 

Vitzthum, H. G. 1935. Uber die Gattung Entonyssus Ewing (Acari). Zeit. 
Parasitenk. 7:709-716. 

Rhinonyssidae Trouessart, 1895 

Figure 60 

Diagnosis: Rhinonyssids are fairly large (from 0.5 to 1.6 mm. in 
length). They are oval in shape and have weakly sclerotized plates. 



80 



Acarology 



The legs are well developed, and all tarsi have pretarsi, caruncles, and 
claws. The dorsal plate is restricted to the propodosoma or has two or 
three plates or is absent. The setae are short on the body and append- 
ages. Stigmata are present with or without short dorsal peritremes. 
Chelicerae generally have small to rudimentary shears. The tritoster- 
num is absent. 




Figure 60 Larinyssiis orbicularis Strandtmann, 1948. Female. 1. Dorsal view. 
2. Dorsal view of palps and tectum. 3. Chela. 4. Ventral view of gnathosoma. 
5. Ventral view. (After Strandtmann 1948) 



Genera and subgenera: 

1. Rhinonyssiis Trouessart, 1894 
a. Rhinonyssiis s. str. 

Type. RJiinonyssus coniventris Trouessart, 1894 



Mesostigmata 81 

b. Cos (New name for Rhinacarus Castro, 1948, Arq. Inst. S. Paulo 
18: 257. Not Rhinacarus Nehring, 1884.) 
Type. Rhinonyssus {Rhinacarus) angrensis Castro, 1948 

2. Larinyssus Strandtmann, 1948 

Type. Larinyssus orbicularis Strandtmann, 1948 

3. Neonyssus Hirst, 1921 (= Neonyssoides Hirst, 1924) 

a. Neonyssus s. str. 

Type. Neonyssus intermedius Hirst, 1921 

b. Paraneonyssus Castro, 1948 

Type. Neonyssus {Paraneonyssus) enriettii Castro, 1948 

c. Rochanyssus Castro, 1948 

Type. Neonyssus {Rochanyssus) werneri Castro, 1948 

d. Travanyssus Castro, 1948 

Type. Neonyssus {Travanyssus) paranensis Castro, 1948 

e. Vitznyssus Castro, 1948 

Type. Dermanyssus nitzchi Giebel, 1871 

4. Ptylonyssoides Vitzthum, 1935 

Type. Ptylonyssoides triscutatus Vitzthum, 1935 

5. Ptilonyssus Berlese and Trouessart, 1889 

a. Ptilonyssus s. str. 

Type. Ptilonyssus echinatus Berlese and Trouessart, 1889 

b. Flavionyssus Castro, 1948 

Type. Ptilonyssus {Flavionyssus) rabelloi Castro, 1948 

c. Rhinonyssoides Hirst, 1921 
Type, Rhinonyssoides trouessarti Hirst, 1921 

6. Rallinyssus Strandtmann, 1948 
Type. Rallinyssus caudistigmus Strandtmann, 1948 

7. Rhinoecius Cooreman, 1946 
Type. Rhinoecius oti Cooreman, 1946 

8. Sommatricola Tragardh, 1904 
Type. Sommatricola levinseni Tragardh, 1904 

9. Sternostoma Berlese and Trouessart, 1889 
Type. Sternostoma cryptorhyneum Berlese and Trouessart, 1889 

10. Sternostomum Trouessart, 1895 

Type. Sternostomum rhinoletrum Trduessart, 1895 

Discussion: Rhinonyssids are viviparous and produce larvae in which 
the nymphs are already developed. They are parasitic in the nasal 
passages of birds all over the world, and probably only a fraction of 
the species has been found since few birds have been examined for 
them. Trouessart reported that they can do damage to chicks. Strandt- 
mann 1948 suggests that it might be interesting to investigate the pos- 
sible role that these mites may play in ornithosis. 




82 



Acarology 



References: 

Bregetova, N. C. 1950. New species of endoparasitic mites of the family 

Rhinonyssidae (Gamasoidea, Acarina). Akad. Nauk. SSSR Dok. 71 

(5): 1005-1008. 
Castro, M. P. de. 1948. Reestrutura9ao generica da familia "Rhinonyssidae 

Vitzthum, 1935" (Acari Mesostigmata: Gamasides) e descri9ao de 

algumas especies novas. Arq. Inst. Biol. Sao Paulo Brasil 18:253-284. 
Strandtmann, R. W. 1948. The mesostigmatic nasal mites of birds. I. Two 

new genera from shore and marsh birds. J. Parasitol. 34:505-514. 
. 1950. The mesostigmatic nasal mites of birds. II. New and poorly 

known species of Rhinonyssidae. J. Parasitol. 37 (2) : 129-140. 
Vitzthum, H. G. 1935. Milben aus der Nasenhole von Vogeln. J. Ornith. 

83:563-587. 










Haemogamasidae Oudemans, 1926 

Figure 61 

Diagnosis: These are medium-sized, oval 
mites. The body is heavily clothed with setae 
that give a furlike appearance on both the dor- 
sal and ventral surfaces. The dorsal plate is 
entire in the larvae, nymphs, and adults. Ven- 
tral plates of males and females that in other 
families have only a few setae may be covered 
by setae in this family. All tarsi are provided 
with pretarsi, caruncles, and claws. The trito- 
sternum is present. The metapodal plates are 
small and the stigmata with long, anteriorly 
directed peritremes are present. The tectum is 
tongue-like and has numerous irregular pro- 
jections. 



Figure 61 Haemoga- 
masiis mandschiiriciis 
Vitzthum, 1930. Ven- 
tral view of female. 
(After Vitzthum 1930) 

Genera: 

1. Haemogamasus Berlese, 1889 

Type. Haemogamasus hirsiitus Berlese, 1889 

2. Acanthochela ¥.\^\ng, \9'}>'i 

Type. Acanthochela chiliensis Ewing, 1933 



Mesostigmata 83 

3. Euhuemogamasus Ewing, 1933 

Type. Euhaemogamasus onychomydis Ewing, 1933 

4. Ischyropoda Keegan, 1951 

Type. Ischyropoda spiniger Keegan, 1951 

Discussion: Keegan 1950 removed Acanthochela from the family 
because he could not determine the nature of the chelicerae or tectum 
on the type material in the United States National Museum. Examina- 
tion of the material with a phase-conlrast microscope reveals that the 
tectum and chelicerae are typical of the Haemogamasidae. 

Haemogamasids are parasitic on small mammals all over the world. 
They frequently spend most of their time in nests and only get on the 
host to feed. They have a typical life cycle and pass through a larval 
and two nymphal stages before becoming adults. The fact that these 
mites are common on small mammals suggests that they may be im- 
portant in the transmission of plague, typhus, tularemia, and perhaps 
other diseases. Investigation of their disease-carrying potentialities is 
yet to be undertaken. 

References: 

Ewing, H. E. 1933. New genera and species of parasitic mites of the super- 
family Parasitoidea. Proc. U.S. Nat. Mus. 82: Art. 30:1-14. 

Keegan, H. L. 1951. The mites of the subfamily Haemogamasinae (Acari: 
Laelaptidae). Proc. U.S. Nat. Mus. 101(3275) :203-268. 

Vitzthum, H. 1930. Milben als Pesttrager? Zool. Jahrb. 60:381-428. 

Dermanyssidae Kolenati, 1859 

Figures 62 — 64 

Diagnosis: Dermanyssids are medium-sized mites. The dorsal plate 
is either undivided in the female or is divided so that the anterior plate 
is large and the posterior one extremely small. The ventral plates of 
the female are typical of the suborder except that they are somewhat re- 
duced. The sternal plate has three pairs of setae, while the metasternal 
plates are reduced and lateral to the genital plate. The genito-ventral 
plate is drop-shaped posteriorly. The anal plate has three characteris- 
tic setae. In the Dermanyssidae the chelicerae may be extremely elon- 
gated and terminate in a minute shear so that they appear to be a pair 
of needle-like structures, or they may be more normal with merely 
reduced chelae. Tritosternum is present. All legs have pretarsi, carun- 
cles, and claws. 



84 
Genera: 



Acarology 



1. Dermanyssus T>ughs, \^2> A 

Type. Acarus gallinae DeGeer, 1778 

2. Allodennanyssiis Ewing, 1923 

Type. Dermanyssus sanguineus Hirst, 1914 





^ ' -X^ 



Figure 62 AUodermanyssus sanguineus (Hirst), 1914. Dorsal and ventral views 
of female. 




Figure 63 Dermanyssus gallinae (Dq- Figure 64 Dermanyssus gallinae (Dt- 
Geer). Ventral view of female. (After Geer). Ventral view of male. (After 
Hirst 1922) Hirst 1922) 



Mesostigmata 85 

3. Bdellony ssus Fonseca, 1941 (= Le io gnat hus CiLnestrini, 1885 

homonym = Liponyssus of authors = Fonsecaonyssus Radford, 
1950) 
Type. Leiognathus bacoti Hirst, 1913 

4. Brevisterna Keegan, 1949 

Type. Euhaemogamasus utahensis Ewing, 1933 

5. Echinonyssus Hirst, 1925 

Type. Echinonyssus nasutus Hirst, 1925 

6. Ellsworthia Turk, 1945 (= Hemilaelaps Ewing, 1923 homonym) 
Type. Hemilaelaps americanus Ewing, 1923 

7. Hirstesia Fonseca, 1948 

Type. Liponyssus sternalis Hirst, 1921 

8. Hir stony ssus Fonseca, 1948 

Type, Dermanyssus arcuatus Koch, 1839 

9. Ichoronyssus Kolenati, 1858 (= Chiroptony ssus Ku%usiox\, 1945 

= Lepronyssus Kolenati, 1858 = Spinolaelaps Radford, 1940) 
Type. Dermanissus scutatus Kolenati, 1856 

10. Kolenationyssus Fonseca, 1948 

Type. Kolenationyssus athleticus Fonseca, 1947 

1 1 . Lepronyssoides Fonseca, 1 943 

Type. Liponissus pereirai Fonseca, 1935 

12. Lipony sella YliYsi, 1925 (= Geneiadolae laps Ewing, 1929) 
Type. Liponyssus madagascarensis Hirst, 1921 

13. Liponyssoidesl:l\v%i,\9\2> 

Type. Dermanyssus (Liponyssoides) muris Hirst, 1913 

14. Macronyssus Kolenati, 1858 

Type. Caris longimana Kolenati, 1856 

15. Manisicola Lawrence, 1939 

Type. Manisicola africana Lawrence, 1939 

16. Manitherionyssus Vitzthum, 1925 

Type. Liponyssus heterotarsus Vitzthum, 1925 

17. Myonyssoides Yiixsi, \925 

Type. Myonyssoides capensis Hirst, 1925 

18. My ony ssus T'lVdihcischi, 1904 (= Tetr agony ssus Ewing, 1923) 
Type. Myonyssus decumani Tiraboschi, 1904 

19. Neoichoronyssus Fonseca, 1943 

Type. Liponissus wernecki Fonseca, 1935 

20. Neoliponyssus Ewing, 1929 (= Oudemansiella Fonseca, 1948) 
Type. Liponyssus gordonensis Hirst, 1923 

21. Ophionyssus Megnin, 1884 (= Serpenticola Ewing, 1923) 
Type. Ophionyssus natricis Megnin, 1884 

22. Tur (New name for Protonyssus Turk, 1947, Ann. Mag. Nat. Hist. 1 1 

14: 348. Not Protonyssus Trouessart, 1915.) 
Type. Protonyssus uniscutatus Turk, 1946 



86 Acarology 

23. Radfordiella Fonseca, 1948 

Type. Radfordiella oudemansi Fonseca, 1948 

24. Steatonyssus Ko\cn2Li\, \^5d, 

Type. Acarus musculi Schrank, 1803 

Discussion: Dermanyssids typically have a larval and two nymphal 
stages before becoming adult males and females. They are parasitic on 
vertebrates and are of considerable economic and medical importance. 
The family is frequently subdivided into two subfamilies, the Derma- 
nyssinae with needle-like chelicerae, and the Liponissinae with more 
normal chelicerae. Only three genera — Dermanyssiis, Liponyssoides, 
and Allodermanyssiis — are included in the Dermanyssinae. Some au- 
thors have given familial standing to the two groups. Fonseca 1948 
has written a monograph of those genera that are sometimes included 
in the Liponissinae or Liponissidae. He, however, refers to the group 
as the Macronyssidae. The arrangement of the genera presented here 
is based largely on Fonseca's 1948 monograph, Vitzthum 1941, and 
the advice of R. W. Strandtmann in litt. The Dermanyssidae are as yet 
poorly known so that the present picture must still be considered as 
tentative. 

Dermanyssus gallinae (DeGeer, 1778) is an important pest of 
domestic birds, especially chickens and pigeons, in all parts of the 
world. Heavy infestation with these mites can cause the death of their 
hosts, while light infestations result in reduced egg production and 
poor growth. The mites normally feed at night and infest the host only 
at this time. During the day they are found in the cracks of roosts, 
coops, and nests. At times they may be so numerous in nests that 
brooding hens will leave their eggs. D. gallinae will also attack man, 
especially children. A family in Durham, North Carolina, complained 
of a severe dermatitis on their baby. The mother and father were not 
affected. Examination of the house revealed numerous specimens of 
D. gallinae on an electric clock in the living room. The clock was 
slightly warmer than the rest of the room and it is probable that the 
mites were attracted to it for this reason. The gutter on the roof of the 
house was used extensively by pigeons and their droppings had col- 
lected in a great pile on the roof of the porch. After removal of 
the droppings and elimination of the pigeons the mites disappeared 
and the child was no longer bothered. Recently the virus of St. Louis 
encephalitis has been recovered from chicken mites and it is suggested 
that D. gallinae serves as a reservoir for the disease (M. G. Smith et 
al. 1948). As more and more work is done on the epidemiology of 



Mesostigmata 87 

human diseases it is probable that many mites will be found to play 
an essential role. 

Allodermanyssus sanguineus (Hirst) is normally a parasite of small 
rodents. It also has the habit of occasionally biting man and has been 
reported from large eastern cities such as Boston, New York, and 
Baltimore as a human parasite. Recently a new disease, rickettsialpox, 
was found to be carried by this mite in New York City. The disease 
was originally confused with chickenpox but intensive work demon- 
strated that it was new (Huebner 1947). 

Bdellonyssus sylviarum (Canestrini and Fanzago), a typical fowl 
mite, is known to harbor neurotropic viruses (Reeves et al. 1949). 
During World War II it was found that Bdellonyssus bacoti Hirst acted 
as the intermediate host of Litomosoides carinii, a filarial worm that 
lives in cotton rats. Since the mites, rats, and worms could be readily 
cultured they were used extensively in investigations on filariasis (Wil- 
liams and Brown 1945). 

References: 

Anderson, C. R. 1944. Rat mite dermatitis. Acariasis caused by the tropi- 
cal rat mite, Liponyssus bacoti Hirst, 1914. Arch. Dermatol, and 
Syphilol. 50(2):90-95. 

Bishopp, F. C. and H. P. Wood. 1939. Mites and lice on poultry. U. S. 
Dept. Agr. Farmers' Bull. 801 : 1-25. 

Fonseca, F. da. 1948. A monograph of the genera and species of Macro- 
nyssidae Oudemans, 1936 (synom. Liponissidae Vitzthum, 1931) 
(Acari). Proc. Zool. Soc. London. 118:249-334. 

Huebner, R. J. 1947. Rickettsialpox a new disease. Amer. J. Clin. Path. 
17:970-971. 

Roueche, B. 1950. The alerting of Mr. Pomerantz. MD. 5(3) : 73-82. 

Smith, Margaret G. et al. 1948. Experiments on the role of the chicken 
mite Dennanyssus gallinae and the mosquito in the epidemiology of 
St. Louis encephalitis. J. Exp. Med. 87:119-138. 

Williams, R. W. and H. W. Brown. 1945. The development of Litomo- 
soides carinii filariid parasite of the cotton rat in the tropical rat mite. 
Science. 102:482-483. 

Phytoseiidae Berlese, 1916 

Figure 65 

Diagnosis: This family includes a rather heterogeneous group of gen- 
era that is characterized by the shape of the epigynial plate. The plate 



88 Acarology 

is truncated or concave posteriorly. The specialized seta on the palpal 
tarsus has two tines. 





Figure 65 Seiulus bakeri Garman, 
1948. Dorsal and ventral views of 
female. (After Garman 1948) 

The family can be subdivided into two subfamilies, the Phytoseiinae, 
recently studied and defined by Garman 1948, and the Podocininae, 
a poorly defined group of genera. These subfamilies can be separated 
as follows: 

Key to the Phytoseiidae 

1, With few setae on dorsal plate; pretarsi, caruncles, and claws on 
all legs; dorsal plate undivided Phytoseiinae 

Without this combination of characters Podocininae 

Phytoseiinae Berlese, 1916 
Genera and subgenera: 

1. Phytoseius Ribaga, 1902 

Type. Gamasus pliimifer Canestrini and Fanzago, 1876 

2. Amblyseius Berlese, 1904 (= Borinquolaelaps Fox, 1946) 
Type. Seius obtusus Berlese, 1889 

3. Amblysiopsis Garman, 1948 

Type. Amblyseius {Amblysiopsis) americanus Garman, 1948 

4. Ameroseius Berlese, 1903 

Type. Acarus corbicula Sowerby, 1806 (= Seius echinatus Koch, 
1839 = Seius muricatus Koch, 1839 = Seius hirsutus Berlese, 
1887, sed non Seius muricatus Berlese, 1887) 

5. Iphidulus Ribaga, 1902 

Type. Iphidulus communis Ribaga, 1902 

6. Lasioseius Berlese, 1916 

a. Lasioseius s. str. 

Type. Lasioseius aba, new name for Seius muricatus Berlese, 1887 

b. Cheiroseius Berlese, 1916 

Type. Seius unguiculatus Berlese, 1916 

c. Leioseius Berlese, 1916 

Type. Ameroseius mimisculus Berlese, 1905 



Mesostigmata 89 

d. Zercoseius Berlese, 1916 

Type. Seius spathuliger Leonard!, 1899 

e. Zygoseius Berlese, 1916 

Type. Zygoseius furciger Berlese, 1916 

7. Melichares Hering, 1838 

Type. Melichares agilis Hering, 1838 

8. 5^/0/75/5 Berlese, 1923 

Type. Ambly seius (Seiopsis) brevipilis Berlese, 1923 

9. Seiulus Berlese, 1887 (= Echinoseius Ribaga, 1902) 
Type. Seiulus hirsutigenus Berlese, 1887 

10. Seius Koch, 1836 

Type. Seius togatus Koch, 1836 

11. Tr/\yromM5 Hughes, 1948 

Type. Tristomus butleri Hughes, 1948 

12. Ty phlodromus Scheuten, 1857 

Type. Gamasus vepallidus Koch, 1839 (= Ty phlodromus pyri 
Scheuten, 1857) 

Podocininae Berlese, 1916 
Genera: 

1. Podocinum Berlese, 1882 

Type. Laelaps sagax Berlese, 1882 

2. Antennoseius Berlese, 1916 

Type. Antennoseius delicatus Berlese, 1916 

3. Asternolaelaps Berlese, 1923 

Type. Asternolaelaps fecundus Berlese, 1923 

4. Asternoseius Berlese, 1910 

Type. Asternoseius ciliatus Berlese, 1910 

5. Blattisocius Keegan, 1944 

Type. Ty phlodromus tineivorus Oudemans, 1929 
(= Blattisocius triodons Keegan, 1944) 

6. Episeiella Willmann, 1938 

Type. Episeiella heteropoda Willmann, 1938 

7. Hoploseius Berlese, 1914 

Type. Zercon cometa Berlese, 1910 

8. Platy seius Berlese, 1916 {-Episeius Hull, 1918) 
Type. Platy seius capillatus Berlese, 1916 

9. Thinoseius Halbert, 1920 

Type. Thinoseius berlesei Halbert, 1920 

10. Zerconopsis Hull, 1918 

Type. Gamasus remiger Kramer, 1876 

11. Iphiseius Berlese, 1916 (This genus was listed by Vitzthum 1941, but 

no type is designated. The original reference has not been located.) 



90 Acarology 

Discussion: Members of the Phytoseiidae are frequently found on 
plants where they are extremely beneficial because they are predaceous 
and help to keep the species that feed on plants in check. Garman 
1948 points out that pesticides that affect this group of mites may be 
harmful if applied to plants because they will allow the plant feeders to 
go unchecked, Garman also discusses the classification of these mites, 
but many of his conclusions are not followed here. 

References: 

Garman, P. 1948. Mite species from apple trees in Connecticut. Conn. 
Agr. Expt. Sta. Bull. 520:1-27. 

Hughes, A. M. 1948. The mites associated with stored food products. Min- 
istry of Agriculture and Fisheries, London, pp. 1-168. 

Keegan, H. L. 1944. On a new genus and species of parasitid mite. J. Para- 
sitol. 30:181-183. 

Lord, F. T. 1949. The influence of spray programs on the fauna of apple 
orchards in Nova Scotia. IIL Mites and their predators. Canad. Ent. 
81 (8):202-214. 



Iphiopsidae Kramer, 1886 
Figure 66 




Diagnosis: The most useful 
characteristic in identifying iphi- 
opsids is the minute peritreme. 
All legs have pretarsi and carun- 
cles. The specialized seta on the 
palpal tarsus has two tines. The 
epigynial plate may be drop- 
shaped or excavated posteriorly. 



Figure 66 Jacobsonia tertia Vitzthum. 
193 L Ventral view of female. (After 
Vitzthum 1931) 



Mesostigmata 91 

Genera: 

1. /p/?/op5/5 Berlese, 1882 

Type. Iphis mirabilis Berlese, 1882 

2. Berlesia Canestrini, 1884 

Type. Berlesia rapcix Canestrini, 1884 

3. Jacobsonia Berlese, 1910 

Type. Iphiopsis {Greeniella) submollis Berlese, 1910 
{Iphis homonym of Iphis Meigen, 1800 and 
Greeniella homonym of Greeniella Cockerell, 1897) 

Discussion: Iphiopsids are parasites or commensals of insects and 
myriopods. They are of no known economic or medical importance. 

Reference: 

Vitzthum, H. G. 1931. Eine afrikanische Jacobsonia (Acari). Zool. Anz. 
96:153-159. 

Laelaptidae Berlese, 1892 

Figures 67, 68 

Diagnosis: Laelaptids have two tines on the specialized seta on the 
palpal tarsus. The epigynial plate is drop-shaped or excavated pos- 
teriorly and the peritreme is elongated. Most species have pretarsi, 
caruncles, and claws on all legs. The dorsal plate is undivided. Coxa ii 
has a toothlike projection from the anterior border. 

The family Laelaptidae as here restricted still includes a large num- 
ber of fairly diverse genera. Vitzthum 1941 includes in the Laelaptidae 
thirteen subfamilies. He was justified in this treatment because of the 
confusion that existed concerning the limits of the subfamilies. While 
this confusion still exists, some recent papers have added light to the 
subject and nine of the subfamilies (Railliettidae — Laelaptidae) have 
been raised to familial rank and the subfamily Podocininae is included 
in the Phytoseiidae. The separations between the families in many 
cases is still not completely clear. There remain in the Laelaptidae 
three subfamilies. The group of genera here included in the Laelap- 
tidae requires a thorough revision and the following grouping follows 
Vitzthum 1941 in most cases and is admittedly unsatisfactory. Much 
study over a long period of time by many investigators must be under- 
taken before a satisfactory classification of this group of mites is 
achieved. The following key will separate most of the species into 
their proper subfamilies. 




Figure 67 Myrmonyssus chapmani Baker and Strandtmann, 1948. Female. 
1, Dorsal view of gnathosoma. 2. Ventral view of gnathosoma. 3. Chela. 4. Dor- 
sal view of female. 5. Ventral view of female. 6. Tarsus i. (After Baker and 
Strandtmann 1948) 




Figure 68 Echinolaelaps echidninus (Berlese), 1887. Ventral view of female. 
(After Hirst 1922) 

92 



Mesostigmata 93 

Key to the Laelaptidae 

1. Anterior border of tectum convex with continuous or serrate 

margin 2 

Anterior margin of tectum with lance-shaped projection 

Hyletastinae 

2. Associated with insects; ventral setae usually weak Hypoaspidinae 

Associated with mammals; ventral setae usually spinelike 

Laelaptinae 

Hyletastinae Vitzthum, 1941 
Genera and subgenera: 

1. Hyletastea Gistel, 1884 (= Iphis Koch, 1836) 
Type. Iphis globulus Koch, 1839 

2. Copriphis Berlese, 1910 

a. Copriphis s. str. 

Type. Iphis pterophilus Berlese, 1882 

b. Peletiphis BQT\ese, 1911 

Type. Copriphis (Peletiphis) insignis Berlese, 1911 

c. Alliphis WdiXhQrX, 1923 

Type. Gamasus halleri G. and R. Canestrini, 1881 

3. Co^m//7/i/5 Vitzthum, 1926 

Type. Emaeus bosschai Oudemans, 1901 

4. Eviphis Berlese, 1903 

a. Eviphis s. str. 

Type. Eumaeus pyrobolus Koch, 1839 

b. Oloiphis Berlese, 1916 

Type. Eviphis magnificus Berlese, 1916 

5. Iphidozercon Berlese, 1903 
Type. Eviphis gibbus Berlese, 1903 

6. Md/mp/z/^ Berlese, 1918 

Type. Laelaps (Iphis) alvearius Berlese, 1895 

7. Uroiphis Berlese, 1903 

Type. Uroiphis scabratus Berlese, 1903 

Hypoaspidinae Vitzthum, 1941 
Genera and subgenera: 

1. Hypoaspis G. Canestrini, 1885 
a. Hypoaspis s. str. 

Type. Laelaps kramerii G. and R. Canestrini, 1881 



94 Acarology 

b. Androlaelaps Berlese, 1903 

Type. Laelaps hermaphrodita Berlese, 1903 

c. Cosmolaelaps Berlese, 1903 

Type. Laelaps claviger Berlese, 1883 

d. Gymnolaelaps Berlese, 1920 

Type. Laelaps myrmecophilus Berlese, 1892 

e. Holostaspis Kolenati, 1858 

Type. Holostaspis isotricha Kolenati, 1858 

f. Laelaspis Berlese, 1903 

Type. I phis astronomicus Berlese, 1889 

g. Leptolaelaps Berlese, 1918 

Type. Hypoaspis {Leptolaelaps) elegans Berlese, 1918 
h. Pneumolaelaps Berlese, 1920 

Type. I phis bombicolens G. Canestrini, 1885 
i. Stratiolaelaps Berlese, 1916 

Type. Laelaps {I phis) miles Berlese, 1882 

2. AnystipalpusBQvXQ^Q, \9\\ 

Type. Anystipalpus percicola Berlese, 1911 

3. Arctoseiusl^hor, \9?>0 

Type. Arctoseiiis lateroincisiis Thor, 1930 

4. Coleolaelaps Berlese, 1914 

Type. Laelaps {I phis) agrestis Berlese, 1887 

5. Dinogamasiis Kramer, 1898 (= Greenia Oudemans, 1901 

= Greeniella Banks, 1904 = Dolaea Oudemans, 1912) 
Type. Dinogamasiis crassipes Kramer, 1898 

6. Iphidosoma Berlese, 1892 {Parasitidael) 
Type. Holostaspis fimetaria Miiller, 1859 

7. Jordensia Oudemans, 1937 
Type. Gamasus cossi Duges, 1834 

8. Julolaelaps Berlese, 1916 

Type. Julolaelaps dispar Berlese, 1916 

9. Laelantermus Berlese, 1916 

Type. Laelantennus lagena Berlese, 1916 

10. Ljiinghia Oudemans, 1932 

Type. Ljunghia selenocosmiae Oudemans, 1932 

11. M eliponaspis y'lizXhum, \9?>0 

Type. Meliponaspis dehilipes Vitzthum, 1930 

12. MyrmeciphisUu\\,\913> 

Type. Myrmeciphis crawleianiis Hull, 1923 

13. Myrmolaelaps Tragkrdh, 1906 

Type. Myrmolaelaps equitans Tragardh, 1906 

14. Myrmoleichus Berlese, 1903 

Type. Myrmoleichus coronatus Berlese, 1903 



Mesostigmata 95 

15. Myrmonyssus Berlese, 1903 

a. Myrmonyssus s. str. 

Type. Myrmonyssus diplogenius Berlese, 1903 

b. Laelaspulus Berlese, 1903 

Type. Myrmonyssus acuminatus Berlese, 1903 

16. Myrmozercon Berlese, 1902 

Type. Myrmozercon brevipes Berlese, 1902 

17. N eoberlesia BqvXq^q, \^92 

Type. Neoberles'a equitans Berlese, 1892 

18. Neocypholaelaps Vitzthum, 1941 (= Cypholaelaps Berlese, a homo- 

nym) 
Type. Laelaps ampullula Berlese, 1892 

19. Ololaelaps Berlese, 1903 

a. Ololaelaps s. str. 

Type. Laelaps venetus Berlese, 1903 

b. Cypholaelaps Berlese, 1916 {non — Cypholaelaps Berlese, 1918) 
Type. Ololaelaps (Cypholaelaps) haemisphaericus Berlese, 1916 

20. Paradoxiphis Berlese, 1910 

Type. Paradoxiphis tennibrachiatus Berlese, 1910 

21. Phytojacobsonia WXzihum, 1925 

Type. Phytojacobsonia irregularis Vitzthum, 1925 

22. Podolaelaps Berlese, 1888 

Type. Podolaelaps ambulacralis Berlese, 1888 

23. Proctolaelaps Berlese, 1914 

Type. Proctolaelaps productus Berlese, 1923 

24. Stamfordia Tragardh, 1906 

Type. Stamfordia carabicola Tragardh, 1906 

25. Stylochirus G. and R. Canestrini, 1882 

Type. Stylochirus rovennensis G. and R. Canestrini, 1882 

26. UrozerconBeiXesQ, 1901 (= TermitacarusTY'3.gkrdh, 1906) 
Type. Urozercon paradoxus Berlese, 1901 

27. Varroa Oudemans, 1904 

Type. Varroa jacobsoni Oudemans, 1904 

Laelaptinae Berlese, 1892 
Genera and subgenera: 

1. Laelaps Koch, 1839 

a. Laelaps s. str. 

Type. Acarus muris Ljungh, 1799 (= Laelaps agilis Koch, 1839) 

b. Eugynolaelaps Berlese, 1918 

Type. Laelaps {Eugynolaelaps) coriaceus Berlese, 1918 

c. Heterolaelaps Hirst, 1926 

Type. Heterolaelaps antipodianus Hirst, 1926 



96 Acarology 

d. Macrolaelaps Ewing, 1929 

Type. Laelaps sangiiisugiis Vitzthum, 1924 

e. Mesolaelaps Hirst, 1926 

Type. Mesolaelaps anomalus Hirst, 1926 

f. Tricholaelaps V'\Xzi\\um,\926 

Type. Laelaps (Tricholaelaps) comarM^ Vitzthum, 1926 

2. Cavilaelaps Fonseca, 1935 

Type. Cavilaelaps bresslaui Fonseca, 1935 

3. Echinolaelaps Ewing, \ 929 

Type. Laelaps echidninus Berlese, 1887 

4. Eubrachy laelaps Ewing, 1929 (= Cyclolaelaps Ewing, 1931) 
Type. Laelaps hollisteri Ewing, 1925 

5. Eulaelaps Berlese, 1903 (= Hemilaelaps Hull, 1918) 

a. Eulaelaps s. str. 

Type. Laelaps stabiilaris Koch, 1839 

b. PseudolaelapsBQvXesQ, \9\6 

Type. Laelaps (Hoplolaelaps) doderoi Berlese, 1910 

6. Gigantolaelaps Fonseca, 1939 

Type. Gigantolaelaps vitzthumi Fonseca, 1939 

7. Haemolaelaps Berlese, 1910 (= A tricholaelaps Ewing, 1929 

3= Ischnolaelaps Fonseca, 1935) 
Type. Laelaps (Haemolaelaps) marsupialis Berlese, 1910 

8. Longolaelaps WXzihum, \916 

Type. Longolaelaps longulus Vitzthum, 1926 

9. Mysolaelaps Fonseca, 1935 

Type. Mysolaelaps parvispinosus Fonseca, 1935 

10. NeolaelapsY{\rsi,\926 

Type. Liponyssus magnistigmatus Vitzthum, 1918 

11. Neoparalaelaps Fonseca., 1935 

Type. Neoparalaelaps bispinosus Fonseca, 1935 

12. Ophidilaelaps Radford, 1947 

Type. Ophidilaelaps imphalensis Radford, 1947 

13. Scissuralaelaps y^omersXey, 1945 

Type. Scissuralaelaps nova-guinea Womersley, 1945 

14. Ugandolaelaps Radford, 1942 

Type. Ugandolaelaps protoxera Radford, 1942 

Unassigned genera: Three genera are based on nymphs and males. 
These cannot properly be included under any subfamily because the 
classification is based primarily on the females. Radford 1942 reports 
that Ligilaelaps and Miingosicola are represented in part by females. 
However, his drawing stated to be a female of Mungosicola ugandae is 
definitely not a female but a nymph. 



Mesostigmata 97 

Genera: 

L Rad (New name for Banksia Radford, 1942. Parasitol, 34:299. 
Not Banksia Voigts and Oudemans, 1905.) 
Type. Laelaps longiseta Banks, 1909 

2. Ligilaelaps Radford, 1 942 

Type. Eulaelaps ewingi Pearse, 1930 

3. Mungosicola Radford, 1942 

Type. Mungosicola ugandae Radford, 1942 

Discussion: Laelaptid mites are world-wide in distribution. They are 
usually parasitic. They parasitize invertebrates as well as vertebrates 
and are the most common ectoparasites of mammals. Their life his- 
tories vary in that larval and nymphal stages can be reduced. No lae- 
laptids have yet been implicated in the transmission of diseases from 
animal to man, but there are so many species and their opportunities 
for acting as vectors are so numerous that they will probably be in- 
criminated when they are investigated. 

Echinolaelaps echidninus (Berlese) transmits Hepatozoan muris 
(Balfour) from rat to rat. This protozoan uses the mites as a defini- 
tive host. It gets into the rat (many species of the genus Rattus serve 
as hosts) when infected mites are ingested. Haemolaelaps arcuatus 
(Koch) transmits Hepatozoan criceti (Danilewsky), a similar proto- 
zoan, to the hamster {Cricetus jrumentarius NoUer). 

As already mentioned, the taxonomy of the laelaptids is extremely 
difficult because of the large number of species; included and the lack 
of careful study. The following references will serve as an introduction 
to the large mass of literature. 

References: 

Berlese, A. 1904. Acari mirmecofili Redia 1:300-474 + Pis. VII-XX. 

Ewing, H. E. 1925. New parasitic mites of the genus Laelaps. Proc. Ent. 
Soc. Wash. 27:1-7. 

Fonseca, F. da. 1939. Notas de acareologia XXV. Os Laelaptidae gigantes, 
parasitas de roedores sul-americanos; genero e especies novas (Acari) . 
Mem. Inst. Butantan. 12:7-101. 

Radford, C. D. 1943. Genera and species of parasitic mites (Acarina). 
Parasitol. 35:58-81. 

Vitzthum, H. G. 1930. Milben als Pesttrager Zool. Jahrb. Syst. 60:381-428. 

Womersley, H. 1937. Studies on Australian Acarina. Laelaptidae. Para- 
sitol. 29:530-538. 



98 



Acarology 



THINOZERCONINA TRAGARDH, 1946 

The dorsal plate is divided into a large propodosomal plate and a 
smaller posterior plate. The peritreme is dorsal in both sexes, while 
the sternal plates are absent or weakly sclerotized in the female ex- 
cept for well-developed jugular plates in the Thinozerconidae. The 
epigynial plate is narrow, has one pair of setae, and is not articulated 
to a ventral plate. The male genital opening is in the sternal plate. 

Key to the Thinozerconina 

1. Jugular plates of female well-developed; male genital opening 
between coxae ni Thinozerconidae 

Female lacking sclerotized jugular plates; male genital opening 
between coxae ii Dasyponyssidae 

Thinozerconidae Halbert, 1915 

Figure 69 

Diagnosis: The thinozerconids are medium-sized mites that have an 
elongated oval shape and are somewhat pointed posteriorly. Their 
dorsal plate is divided into two and is partially flanked by the dorsal 





Figure 69 Thinozercon michaeli Halbert, 1915. Ventral plates (right) and 
tritosternum (left) of female. (After Tragardh 1946) 



peritremal plates. The epigynial plate is narrow and tongue-like with 
one pair of setae posteriorly. The male genital opening is small and is 
closed by a pair of minute semicircular plates, the first of which carries 
a pair of stout setae. 



Mesostigmata 99 



Genera: 



\. Thinozercon Halbert, 1915 

Type. Thinozercon michaeli KsilbeTt, 1915 
2. Dithinozercon Berlese, 1916 

Type. Thinozercon {Dithinozercon) halberti Ber\ese, 1916 

Discussion: This family is very poorly known. Both included genera 
are monotypic. Thinozercon is from the Old World, and Dithinozercon 
from the New. Probably many new forms in this group await dis- 
covery. 

References: 

Berlese, A. 1916. Centuria terza di acari nuovi Redia 12:295. 
Halbert, J. N. 1915. Clare Island Survey, part 39:11. Proc. Roy. Irish 
Acad. 31:82. 

Dasyponyssidae Fonseca, 1940 

Figures 70-73 

Diagnosis: Both sexes have a divided dorsal plate. The peritreme of 
the female extends dorsally and transversely between the anterior and 
posterior sections of the dorsal plates, while that of male flanks the 
anterior dorsal plate for a short distance. Leg i of both sexes is re- 
markably enlarged so that it is more than twice as stout as legs ii-iv. 
Body setae show some sexual dimorphism, those of the female being 
expanded, while those of the male are normal. Ventral plates of the 
male are divided. Sternal plates i and ii are fused to a single plate in 
which the male genital opening is situated. Sternal plates iii and iv 
are fused on each side but are separated at the midline. The ventral 
plate is reduced and has a single pair of setae. The anal plate has seven 
pairs of setae and one median posterior seta. 

Genus: 

Dasyponyssus Fonseca, 1940 

Type. Dasyponyssus neivai Fonseca, 1940 

Discussion: Dasyponyssus neivai was discovered in Brazil on an ar- 
madillo. It is here placed in the Thinozerconina because of its obvious 
morphological affinities with Thinozercon. It does, however, show 
some relationship to the Gamasides and may even represent a distinct 




Figure 70 Dasyponyssus neivai Fonseca, 1940. Dorsal view of male. (After 
Fonseca 1940) 




Figure 71 Dasyponyssus neivai Fonseca, 1940. Ventral view of male. (After 
Fonseca 1940) 

100 




Figure 72 Dasyponyssus neivai Fonseca, 1940. Dorsal view of female. (After 
Fonseca 1940) 




Figure 73 Dasyponyssus neivai Fonseca, 1940. Ventral view of female. (After 
Fonseca 1940) 

101 



102 Acarology 

group. Additional data are required before this family can be included 
with certainty in any group. 

Reference: 

Fonseca, F. da. 1940. Notas de Acareologia. XXIV. Dasyponyssus neivai 
gen. n., sp. n., acariano parasita de Eiiphractus sexcinctiis (L.) 
Acari, Dasyponyssidae fam. n.). Rev. Ent. Rio de Janeiro 11:104- 
119, 5 figs. 

DIARTHROPHALLIN A TRAGARDH, 1946 

The penis is biarticulated, directed posteriorly, and situated in a 
groove between coxae in. Prestemal setae are present. The epigynial 
plate is enclosed in the fused sternal and ventral plates but is not sepa- 
rated from the ventral plate by a suture. Only one family is known. 



Diarthrophallidae Tragardh, 1946 

Figures 74, 75 

Diagnosis: Diarthrophallids 
are characterized in addition 
to the fundamental structures 
mentioned in the subordinal 
diagnosis by many other fea- 
tures. Leg I is modified as a 
tactile organ and lacks a car- 
oncle and claws. Legs ii-iv 
have a well-developed ambul- 
acral apparatus. The setae on 
the dorsal side are long and 
stiff and in the living mite pro- 
ject dorsally. The dorsal plate 
is entire. 



Figure 74 Diarthrophallus quer- 
ciis (Pearse and Wharton), 1936. 
Ventral view of nymph. (After 
Tragardh 1946) 




Mesostigmata 



103 



Genera: 



1. Diarthrophallus Tr'igkrdh, 1946 

Type. U rose jus querciis Pearse and Wharton, 1936 

2. Brachytremella Tragardh, 1946 

Type. Brachytremella spinosa Tragardh, 1946 

3. Passalobia Lombardini, 1926 

Type. Passalobia quadricaudata Lombardini, 1926 




Figure 75 Diarthrophallus quercus (Pearse and Wharton), 1936. Ventral 
plates of male (left) and female (right). (After Tragardh 1946) 



Discussion: Diarthrophallids are similar to the uropodids in general 
appearance. However, as Tragardh 1946 points out they are amply 
distinct. All members of the family are found on beetles of the family 
Passalidae. They have been found in South America, North America, 
Central America, and New Guinea. 

D. quercus Pearse and Wharton, 1936, is common on passalid 
beetles in the vicinity of Durham, North Carolina. 



Reference: 

Tragardh, I. 1946. Diarthrophallina, a new group of Mesostigmata, found 
on passalid beetles. Entom. Medd. 24:370-394. 



104 



Acarology 



ZERCONINA TRAGARDH, 1944 

This suborder is directly related to the Gamasides, and if it were not 
for the position of the male genital opening in the center of the sternal 
plate it would most certainly be included with the Gamasides. Only 
one family is recognized in this group and thus its morphology can be 
discussed at the familial level. 



Zerconidae Berlese, 1892 

Figure 76 

Diagnosis: Zerconids are small 
mites with flat bodies that are 
broadest in the posterior region 
so that they have a somewhat tri- 
angular shape. Their dorsal plate 
may or may not be divided. Tar- 
sus I lacks caruncles and fre- 
quently has a reduced pretarsus, 
while tarsi ii, in, and iv are all 
provided with pretarsi, caruncles, 
and claws. The ventroanal plate 
is large and broad. The male 
genital opening is located in the 
middle of the sternal plate and is 
closed by a double plate attached 
at its anterior margin. The epigy- 
nial plate has only one pair of 
setae and is not fused to the endopodal plates. The metasternal plates 
are so weakly sclerotized that their position can be detected only by 
the presence of the metasternal setae. The sternal plate has the usual 
three pairs of sternal setae. 

Genera: 

1. Zercon Koch, 1836 

Type. Zercon dimidatus Koch, 1841 

2. Parazercon Tragardh, 1931 

Type. Zercon scircikensis Willmann, 1939 
(= Zercon ornatus Tragardh, 1910, 
non Zercon ornatus Berlese, 1904) 




Figure 76 Prozercon kochi Willmann, 
1943. Ventral view of female. (After 
Willmann 1943) 



Mesostigmata 105 

3. Proz^rco^ Willmann, 1943 

Type. Zercon fimhriatus Koch, 1839 

4. Seiodes Berlese, 1887 

Type. Seioides ursinus Berlese, 1887 

5. Triangulazercon Jacot, 1938 
Type. Zercon peltatus Koch, 1836 

(= Zercon triangularis Koch, 1836) 

6. Trizerconoides Jacot, 1938 

Type. Zercon radiatus Berlese, 1910 

Discussion: Zerconids belong to the large fauna that inhabits the 
upper layers of the soil, litter, and beds of moss. They are of no known 
economic or medical importance. 

Rejerences: 

Jacot, A. P. 1938. The Geenton mites of Florida. Florida Ent. 21:49-57. 
Tragardh, I. 1946. Outlines of a new classification of the Mesostigmata 

(Acarina) based on comparative morphological data. Lands Univ. 

K. Fysiogr. Sallsk. Handl. N. F. Bd. 57 Nr. 4:1-37. 

TRACHYTINA TRAGARDH, 1937 

Tragardh 1941 gives a good account of this group (cohort of Tra- 
gardh) and he divides it into three families that are obviously closely 
related. Therefore, a diagnosis of the group will be given along with 
Tragardh's key to the families, and a separate diagnosis for each fam- 
ily will be omitted. The same plan will be followed for the discussion 
and reference in order to avoid repetition. 

Diagnosis: They are intermediate between the Gamasides and Uro- 
podina. The articulations of coxae i are similar to the Gamasides in 
that the coxae do not cover the broad-based tritosternum. The genital 
openings are similar to but not identical with those of the Uropodina. 
The metasternal plate in the female is not fused with the sternal and 
ventral plates and is situated lateral to the epigynial plate. In adults 
the dorsal surface is covered by nymphal skins. The habit of the reten- 
tion of the cast nymphal skins is unusual in the Mesostigmata and is 
restricted to the Trachytina. However, several of the Oribatei exhibit 
this peculiar phenomenon. 



106 



A carology 



Key to the Trachytina 

(after Tragardh, 1941) 

Epigynial plate hinged to ventral plate 2 

Epigynial plate fused with ventral plate Polyaspidae 

Metasternal plates narrow, elongated, flanking sides of epigynial 
plate Trachytidae 

Metasternal plates almost obliterated, only traces being left in 
posterior angles of genital orifice Polyaspinidae 



Genera: 



Trachytidae Tragardh, 1938 

Figure 77 



1. rrac/7y/^5 Michael, 1894 

Type. Celaeno aegrota Koch, 1841 

2. Neoseius Oudemans, 1903 (? deutonymph only known stage) 
Type. Uroseius novus Oudemans, 1902 

3. Uroseius Berlese, 1888 

Type. Uropoda acuminata Koch, 1847 





Figure 77 Trachytes aegrota (Koch), Figure 78 Dipolyaspis sansonei Ber- 
1841. Dorsal view of female. (After lese, 1916. Ventral view of female. 
Tragardh 1941) (After Tragardh 1941) 



Mesostigmata 



107 



Polyaspidae Berlese, 1917 

Figure 78 



Genera: 



3. 



Polyaspis Berlese, 1881 

Type. Polyaspis patavinus Berlese, 1881 

Calotrachytes Berlese, 1916 

Type. Trachynotus fimbriatus Michsie], 1908 

Dipolyaspis Berlese, 1916 

Type. Polyaspis {Dipolyaspis) sansonei Berlese, 1916 



Polyaspinidae Tragardh, 1941 

Figure 79 



Genus: 



Polyaspinus Berlese, 1916 

Type. Polyaspinus cylindricus Berlese, 1916 




Discussion: Little is known 
about the life of this interesting 
group of mites. Tragardh finds 
them under the bark of decayed 
stumps so that they are probably 
found in concentrations of rot- 
ting organic matter high in cel- 
lulose. This group is of no known 
medical or economic importance. 



Figure 79 Polyaspinus cylindricus 
Berlese, 1916. Ventral view of female. 
(After Tragardh 1941) 



Reference: 

Tragardh, I. 1941. Further contributions towards the comparative mor- 
phology of the Mesostigmata III. On the Polyaspididae. Berl. Zool. 
Bidrag. F. Uppsala 20:345-357. 



108 



Acarology 



UROPODINA KRAMER, 1881 

The Uropodina are characterized (except for the intermediate group 
of genera in the family DiscoureUidae) by the arrangement of the 
gnathosoma. The anterior ventral portion of the body is excavated so 
that the gnathosoma and tritosternum are enclosed in a cavity, the 
dorsal wall of which is formed by the body wall while coxae i can 
close it ventrally. This cavity is frequently called a camerostome. The 
metasternal plates of this group are also either greatly reduced {JJro- 
diaspis and Uroplitella) or completely absent. The male genital open- 
ing is in the center of the sternal plate, as is the epigynial plate. The 
tritosternum is frequently divided into three lacinae anteriorly. The 
dorsal plate is usually entire in the adults. Depressions for the legs are 
found on the ventral surface so that the short legs may be folded com- 
pactly against the body. The stigmata are opposite leg ii or in. The 
peritremes are usually convoluted to conform to the ridges that limit 
the depressions into which the legs can be folded. The chelicerae 
usually extend for some distance into the idiosoma and in some cases 
may almost reach the posterior end. 

Twelve families are placed in this group with assurance. Two other 
families that are questionable are included here. The Trematuridae 
Berlese, 1917 was supposedly characterized by the presence of four 
stigmata. Tragardh 1942 has shown Berlese to be in error as regards 
the number of stigmata, but Tragardh was unable to clarify the system- 
atic position of Trematura patavina (Canestrini), 1885 with the aid 
of Berlese's specimens. The family DiscoureUidae lacks the camero- 
stome and is thus intermediate between the Uropodina and the Trachy- 
tina. A key to the families modified from Tragardh 1944 follows. 




Figure 80 The arrangement of the dorsal 
plates of representative genera of the 
Uropodina, Top row, from left to right, 
Phaiilodiaspis, Urodiaspis, Oodinychiis; mid- 
dle row, Phaidodinychits, Trematiirella, Pliyl- 
lodinychiis; and bottom row, Eiitrachytes, 
Cilliba, Urodinychus. (After Tragardh 1944 
and Vitzthum 1935) 



Mesostigmata 109 

Key to the Uropodina 

1. Camerostome present 2 ^ 
Camerostome absent Discourellidae 

2. Dorsal plate restricted to dorsal surface 3 ^ 

Dorsal plate extends laterally and ventrally so that only central 
portion of ventral surface not covered by dorsal plate 

Coxequesomidae 

3. Ventral, posterior, marginal plates absent 4 
A pair of ventral, posterior, marginal plates present Planodiscidae 

4. Dorsal marginal plate present 5 -' 
Dorsal marginal plates absent Circocyllibanidae 

5. Stigmata opposite coxae ii or between ii and in 7 " 
Stigmata opposite coxae iii 6 

6. Tritosternum covered by coxae i Trematuridae 
Tritosternum not covered by coxae i Cillibidae 

7. Anterior ends of marginal plate fused with dorsal plate anteriorly 8 

Anterior ends of marginal plate not fused with dorsal plate 

Trematurellidae 

8. Depressions to accommodate legs present 10 
Depressions to accommodate legs absent 9 

9. Distinct posterior dorsal plate present Eutrachytidae 
Posterior dorsal plate not distinct Prodinychidae 

10. Posterior dorsal plate absent 11 \ 
Posterior dorsal plate present Urodiaspidae 

11. Marginal plates fused with dorsal plate 12 
Marginal plates fused with ventral plate Trachyuropodidae 

12. Marginal plate completely surrounds dorsal plate 13 
Marginal plate reduced posteriorly Phaulodinychidae 

13. Marginal plate scalloped on its inner border Urodinychidae 
Marginal plate not scalloped Uropodidae 



110 



Acarology 



In order to make the above key more readily understandable 
sketches of the arrangement of the dorsal plates in representative 
genera are shown in Figure 80. 



Discourellidae 

(New name for Protouropodidae Tragardh, 1941) 

Figure 81 

Diagnosis: To the Discourellidae belong those genera that lack a 
camerostome that is protected by the first pair of coxae but that have 
an epigynial plate characteristic of the suborder Uropodina. The tri- 
tosternum in this family is unusual in that it is broad at the base. 





[11 


/ 




Figure 81 Discourella modesta Leonardi, 1900. Left, ventral view of female 
and Apionoseiiis lagenaeformis (Berlese), 1904; right, ventral view of female. 
(After Tragardh 1941) 



Genera: 



3. 



Discourella Berlese, 1910 

Type. Discopoma venusta Berlese, 1884 

{—Discourella discopomoides Berlese, 1910) 
Apionoseius Berlese, 1904 
Type. Trachytes lagenaeformis Berlese, 1904 
Polyaspidella Berlese, 1910 
Type. Polyaspidella herenicea Berlese, 1910 



Discussion: Tragardh 1941 proposed the familial name Protouro- 
podidae for the family. The name Discourellidae is here suggested for 



Mesostigmata 



111 



the group and the genus Discourella Berlese, 1910 is considered the 
type of the family. The family is clearly intermediate between the Uro- 
podina and Trachytina. Specimens of the family have been found in 
Canada, Austria, and Java. The family is probably universally dis- 
tributed. Its habits are similar to other members of the Uropodina. 
Discourellids are of no known economic or medical importance. 

Reference: 

Tragardh, I. 1941. Further contributions towards the comparative mor- 
phology of the Mesostigmata, III. On the Polyaspididae. Berl. Zool. 
Bidrag. Uppsala 20:345-357. 



Coxequesomidae Sellnick, 1926 

Figure 82 

Diagnosis: The tritostemum is covered by the first pair of coxae. 
Grooves for the legs are flat. The genital and anal openings are each 
surrounded by a discrete plate. The dorsal plate extends laterally and 
ventrally so that it covers all but the central portion of the ventral 
surface. 




Figure 82 Coxeqiiesoma collegianonim Sellnick, 1926. Ventral view of female. 
(After Sellnick 1926) 

Genera: 

1. Coxequesoma Sellnick, 1926 

Type. Coxequesoma coUegianorum Sellnick, 1926 

2. Antennequesoma Sellnick, 1926 

Type. Antennequesoma reichenspergeri SeWnick, 1926 



112 Acarology 

Discussion: Coxequesomids are myrmecophiles. They are of no known 
economic or medical importance. 

Reference: 

Sellnick, Max. 1926. Alguns novos Acaros (Uropodidae) myrmecophilos 
e termitophilus. Arch. Mus. Rio de Janeiro 26:29-56, 27 figs. 



Planodiscidae Sellnick, 1926 



Figure 83 




Diagnosis: The tritosternum is 
covered by coxae i. The grooves 
for the legs are well developed. 
The anal and genital openings are 
in a single ventral plate. There is 
a ventral marginal plate on either 
side at the posterior end of the 
body. The dorsal plate is not sur- 
rounded by a dorsal marginal 
plate. 



Figure 8^ Planodisciis sqimmatiim 
Sellnick, 1926. Ventral view of female. 
(After Sellnick 1926) 



Genus: 

Planodiscus Sellnick, 1926 

Type. Planodiscus squamatum Sellnick, 1926 

Discussion: Planodiscids are of no known economic or medical im- 
portance. The only representative of the family was found associated 
with ants. 



Reference: 

Sellnick, Max. 1926. Alguns novos Acaros (Uropodidae) myrmecophilos 
e termitophilus. Arch. Mus. Rio de Janeiro 26:29-56, 27 figs. 



Mesostigmata 



113 



Circocyllibanidae Sellnick, 1926 

Figure 84 




Diagnosis: The tritosternum is 
covered by coxae i. The grooves 
for the legs are well developed. 
The genital and anal openings are 
located in separate plates. The 
dorsal plate is not surrounded by 
a dorsal marginal plate. 



Figure 84 CircocyUiba camerata Sell- 
nick, 1926. Ventral view of female. 
(After Sellnick 1926) 



Genus: 

CircocyUiba Sellnick, 1926 

Type. CircocyUiba camerata Sellnick, 1926 

Discussion: C. camerata is a myrmecophile and is of no known eco- 
nomic or medical importance. 

Reference: 

Sellnick, Max. 1926. Alguns novos Acaros (Uropodidae) myrmecophilos 
e termitophilus. Arch. Mus. Rio de Janeiro 26:29-56, 27 figs. 



Trematuridae Berlese, 1917 

Figure 85 

Diagnosis: The tritosternum is covered by coxae i. The grooves for 
the legs are strongly developed. The dorsal plate is surrounded by a 
marginal plate that has smooth, inner borders. Stigmata are in the 
grooves for leg iii. The plates are strongly sculptured. 



Genus: 



Trematura Berlese, 1917 

Type. Uropoda patavina G. Canestrini, 1885 




114 Acarology 

Discussion: Tragardh 1942 studied specimens of T. patavina from 
the Berlese collection. He was unable to work out its morphology 
satisfactorily, and therefore he does not include the family in his 1944 
account of the Uropodina. The Trematuridae are included in this ac- 
count, as are the three previous families proposed by Sellnick 1926, 
as they are in Vitzthum's key work of 1941. T. patavina is of no 
known economic or medical importance. 



Figure 85 T re mat lira patavina (Canestrini), 1885. Portion 
of venter to show stigma and peritreme. (After Tragardh 
1942) 



Reference: 

Tragardh, I. 1942. Uber die Trematurini Berlese (Acarina). Zool. Anz. 
139:109-112. 



Trematurellidae Tragardh, 1944 

Figure 80 

Diagnosis: The dorsal and ventral plates are deeply sculptured. The 
marginal plates are completely separated from the ventral plate and 
dorsal plate by a thin membrane. The dorsal plate is undivided and 
the marginal plate is cleft by a suture anteriorly. 

Genus: 

Trematurella Tmgkrdh, 1942 

Type. Trematurella stylifera Tragardh, 1942 

Discussion: T. stylifera is of no known economic or medical impor- 
tance. 



Reference: 

Tragardh, I. 1942. Uber die Trematurini Berlese (Acarina). Zool. Anz. 
139:109-112. 



Mesostigmata 



115 



Cillibidae Tragardh, 1944 

Figure 86 



Diagnosis: The tritosternum is 
not covered by coxae i. The mar- 
ginal plate is continuous anteri- 
orly but is distinct from the dorsal 
plate. The posterior region of the 
dorsal plate is indistinctly sepa- 
rated from the rest of the dorsal 
plate by a suture. The stigmata 
are located opposite coxae iii. 
Grooves for the legs are well de- 
veloped. 



Genera: 




Figure 86 Thrichocylliba comata (Le- 
onardi), 1895. Ventral view of female. 
(After Berlese 1904) 



1. Cilliba V. Heyden, 1827 (= Discopoma G. and R. Canestrini, 1882) 
Type. Notaspis cassideus Hermann, 1804 

2. Thrichocylliba Berlese, 1904 

Type. Discopoma comata Leonardi, 1895 



Discussion: 
tance. 



Cillibids are of no known economic or medical impor- 



Rejerence: 

Tragardh, I. 1944. Zur Systematik der Uropodiden. Ent. Tidsk. 65:173- 
186. 



Eutrachytidae Tragardh, 1944 

Figure 80 

Diagnosis: In this family the marginal plate is fused anteriorly with 
the dorsal plate. A distinct posterior, dorsal plate is present, but 
grooves for the legs are absent. 



Genus: 



Eutrachytes Berlese, 1914 
Type. Celaeno truncata Berlese, 1 



116 



Acarology 



Discussion: This family is of no known economic or medical impor- 
tance. 

Reference: 

Tragardh, I. 1944. Zur Systematik der Uropodiden. Ent. Tidsk. 65: 
173-186. 



Prodinychidae Berlese, 1916 

Figure 87 




Diagnosis: The tritosternum is 
covered by coxae i. Grooves for 
the legs are either absent or 
poorly developed. The marginal 
plate is continuous posteriorly 
and fused with the dorsal plate 
anteriorly. When the plates are 
separated the marginal plate 
clings to the ventral plate. 



Figure 81 Prodinychus formicarius 
Vitzthum, 1925. Ventral view of male. 
(After Vitzthum 1940) 



Genera: 

1. Pro^myc/7M5 Berlese, 1913 

Type, Dinychiis fimicolus Berlese, 1903 

2. Clausiadinychus Sellnick, 1930 

Type. Clausiadinychus cristatus Sellnick, 1930 

3. Dentidinychus Sellnick, 1926 

Type. Dentidinychus zikani Sellnick, 1926 

4. Dinychus Kramer, 1882 

Type. Dinychus perforatus Kramer, 1882 

5. Discotrachytes ^ev\esQ, \9\6 

Type. Discotrachytes splendidiformis Berlese, 1916 

6. Metadinychus Berlese, 1916 

Type. Metadinychus argasiformes Berlese, 1916 



Mesostigmata 



117 



7. Trichodinychus Berlese, 1916 

Type. Uropoda vulpimi Berlese, 1888 

8. Urolaelaps Berlese, 1916 

Type, Urolaelaps macropi Berlese, 1916 

Discussion: Vitzthum proposed the name Dinychidae for this fam- 
ily in 1931. The family is of no known economic or medical impor- 
tance. 



Reference: 

Tragardh, I. 
186. 



1944. Zur Systematik der Uropodiden. Ent. Tidsk. 65:173- 



Urodiaspidae Tragardh, 1944 

Figure 88 

Diagnosis: The marginal plate is fused to the dorsal plate anteriorly. 
When dissected the dorsal plate clings to the marginal plate. A large, 
distinct, posterior dorsal plate is present. Metasternal plates are also 
present but they are very small at the posterior comers of the epigynial 
plate. 





Figure 88 Urodiaspis tecta (Kramer), 1876. Female dorsum (left) and venter 
(right). (After Berlese 1887) 



Genera: 

1. Urodiaspis Berlese, 1916 

Type. Uropoda tecta Kramer, 1 876 

2. Diurodinychus Berlese, 1916 

Type. Urodiaspis {Diurodinychus) rectangulovatus Berlese, 1916 



118 Acarology 

Discussion: This family is of no known economic or medical impor- 
tance. 

Reference: 

Tragardh, I. 1944. Zur Systematik der Uropodiden. Ent. Tidsk. 65:173- 
186. 

Trachyuropodidae Berlese, 1917 

Figure 89 

Diagnosis: In the trachyuropodids the tritosternum is hidden by coxae 
I. Grooves for the legs are well developed. All the plates are sculp- 
tured. The marginal plate is fused to the ventral plates, and no pos- 
terior dorsal plate is present. 





Figure 89 Trachyiiropoda crustosa Vitzthum, 1926. Lateral (left) and ventral 
(right) views of female. (After Vitzthum 1926) 

Genera and subgenera: 

1. Trachyuropoda Berlese, 1888 (= Michaeliella Berlese, 1904) 

a. Trachyuropoda s. str. 

Type. Trachyuropoda f estiva Berlese, 1888 

b. Dinychura Berlese, 1913 

Type. Trachyuropoda (Urojanetia) rectangula Berlese, 1913 

c. Urojanetia Berlese, 1913 {— Janetiella Berlese, 1904 nom. prae- 

occ.) 
Type. Uropoda coccinea Michael, 1891 

2. Cephalouropoda Berlese, 1903 

Type. Uropoda berlesiana Berlese, 1887 



Mesostigmata 119 

3. Corny dinychus Berlese, 1917 

Type. Uropoda caputmedusoe BerlcsQ, 1901 

4. Deraiophorus G. Canestrini, 1897 

Type. Deraiophorus chyzeri Canestrini, 1897 

5. Dinychopsis Berlese, 1916 

Type. Dinychopsis fractus Berlese, 1916 {non Dinychus appendicu- 
latus Berlese, 1910) 

6. Leonardiella Berlese, 1904 

Type. Uropoda canestriniana Berlese, 1891 

7. Neodiscopoma Vitzthum, 1941 (= Discopoma G. and R. Canestrini 

in the sense of Berlese, 1904) 

a. Neodiscopoma s. str. 

Type. Uropoda splendida Kramer, 1882 

b. Capitodiscus Vitzthum, 1931 (= Cephalodiscus Berlese, 1916 

nom. praeocc.) 
Type. Discopoma venusta Berlese, 1884 

c. Crinitodiscus SQWmd^, 1931 

Type. Discopoma (Crinitodiscus) beieri Sellnick, 1931 

d. Olodiscus Berlese, 1917 

Type. Discopoma integra Berlese, 1910 

e. Phymatodiscus Berlese, 1917 

Type. Discopoma miranda Berlese, 1904 

8. Vropolyaspis Berlese, 1903 

Type. Uropoda hamulifera Michael, 1894 

9. (/ro5/7ma Sellnick, 1931 

Type. Uropoda plana Sellnick, 1931 

Discussion: Like many other families of the Uropodina the trachy- 
uropodids are frequently found associated with ants. They are of no 
known economic or medical importance. 

Reference: 

Tragardh, I. 1944. Zur Systematik der Uropodiden. Ent. Tidsk. 65:173- 
186. 



Phaulodinychidae Berlese, 1917 

Figure 90 

Diagnosis: The tritosternum is covered by coxae i. Grooves for the 
legs are well developed. The single ventral plate is not fused to the 
marginal or dorsal plates. The marginal plate is reduced posteriorly. 



120 
Genera: 



Acarology 



1. Phaulodinychus Berlese, 1903 (= Halouropoda Halbert, 1915) 
Type. Phaulodinychus repletus Berlese, 1903 

2. Diphaulocylliba Vitzthum, 1925 

Type. Phaulocylliba amplior Berlese, 1923 

3. P/z««/ocy///7?fl Berlese, 1903 

Type. Phaulocylliba ventricosa Berlese, 1903 

4. Phaulodiaspis Vitzthum, 1925 

Type. Urodiscella advena Tragardh, 1912 





Figure 90 Phaulodiaspis advena (Tragardh), 1912. Dorsal view of female 
(left): tritosternum (center); ventral view of female (right). (After Tragardh 
1912) 

Discussion: This family is of no known economic or medical impor- 
tance. 

Reference: 

Tragardh, I. 1944. Zur Systematik der Uropodiden. Ent. Tidsk. 65:173- 
186. 



Urodinychidae Berlese, 1917 

Figure 91 

Diagnosis: The tritosternum is covered by coxae i. Well-developed 
grooves are present for the le^s. The marginal plate is continuous pos- 
teriorly and its inner margin is scalloped. 



Mesostigmata 



121 



Genera and subgenera: 

1. Urodinychiis Berlese, 1903 

a. Urodinychus s. str. 

Type. Uropoda corinato Berlese, 1888 

b. Leiodinychus Berlese, 1917 

Type. Uropoda krameri G. and R. Canestrini, 1882 

c. Macrodinychus Berlese, 1917 

Type. Urodinychus parallelepipedus Berlese, 1916 

2. Calurodiscus Radford, 1950 (= Urodiscus Berlese, 1916, nom. prae- 

occ.) 
Type. Urodiscus obesus Berlese, 1916 




'<^>r 



Figure 91 Urodinychus polyphemus Vitzthum, 1935. Dorsal (left) and ventral 
(right) views of male. (After Vitzthum 1935) 

Discussion: This family is of no known economic or medical impor- 
tance. 

Reference: 

Tragardh, L 1944. Zur Systematik der Uropodiden. Ent. Tidsk. 65:173- 
186. 



Uropodidae Berlese, 1917 

Figure 92 

Diagnosis: The tritosternum is covered by coxae i. Grooves for the 
legs are well developed. The marginal plate is fused anteriorly to the 
dorsal plate, but the inner surface of the marginal plate is not scal- 
loped. The plates appear to be mirror-smooth even when they are 
more or less finely punctated. 



122 



Acarology 




Figure 92 Uropoda pearsei Wharton, 1938. 
Ventral plates of female (left) and ventral 
view of male (right). (After Wharton 1938) 




Genera and subgenera: 

1. Uropoda ^^^\.VQ\\\Q, 1806 {— Nummulus BqxXqsq, 1884) 

Type. Accirus orbicularis Mialler, 1776 (= Acariis vegetans Latreille, 
1806 = Discopoma romana G. and R. Canestrini, 1882 in the 
sense of Berlese, 1884, sed non — Acarus vegetans DeGeer, 
1768) 

2. Centrouropoda Berlese, 1916 

Type. Uropoda rhombogyna Berlese, 1910 

3. Cyclacarus Ewing, 1933 

Type. Cyclacarus aberrans Ewing, 1933 

4. Cyllibula Berlese, 1916 

Type. Cillihano {Cyllibula) infumata Berlese, 1916 

5. Encylliba Berlese, 1917 

Type. Cilliba bordagei Oudemans, 1912 

6. Fuscuropoda Wizihum, 1924 

Type. Notaspis /narginatus C. L. Koch, 1839 

7. Marginura Sellnick, 1926 

Type. Marginura adhaerens Sellnick, 1926 

8. Metagynella Berlese, 1919 

Type. Metagynella paradoxa Berlese, 1919 

9. Olouropoda Berlese, 1916 

Type. Uropoda {Olouropoda) nitidissima Berlese, 1916 

10. Oplitis Berlese, 1884 (= Uroplitella Berlese, 1904) 
Type. Uropoda paradoxa G. Canestrini and Berlese, 1884 

11. Pseudouropoda Oudemans, 1936 (= Notaspis C. L. Koch, 1836, sed 

non Notaspis Hermann, 1804; = Uropoda Berlese, 1917) 



Mesostigmata 123 

a. Pseudouropoda s. str. 

Type. Acarus vegetans DeGeer, 1768 

b. Calouropoda Berlese, 1916 

Type. Uropoda pergitta Berlese, 1 904 

c. Trichouropoda Berlese, 1916 

Type. Uropoda longiseta Berlese, 1888 

12. Vrodiscella Berlese, 1903 

Type. Uropoda ricasoliana Berlese, 1889 

13. C/roo^ovW/rt Berlese, 1 903 

a. Uroobovella s. str. 

Type. Uropoda obovata G. Canestrini and Berlese, 1884 

b. Urocyclella Berlese, 1913 

Type. Uroobovella {Urocyclella) parvula Berlese, 1913 

14. Uroplitana Sellnick, 1926 

Type. Uroplitana acinaca Sellnick, 1926 

15. Urosternella Berlese, 1903 

Type. Uropoda {Urosternella) foraminifera Berlese, 1903 

Uncertain genera: 

1. Liponissus Kolenati, 1858 {non Liponyssus of authors) 
Type. Dermanissiis setosus Kolenati, 1856 

2. Neuteria Oudemans, 1905 

Type. Uropoda tropica Oudemans, 1905 

3. Paulitzia Oudemans, 1915 

Type. Uropoda africana Oudemans, 1905 

Discussion: Like the other families, uropodids are of no known eco- 
nomic or medical importance. They are world-wide in distribution and 
frequently attach themselves to insects, especially in the nymphal 
stages. They probably do no harm to their hosts. 

Reference: 

Tragardh, L 1944. Zur Systematik der Uropodiden. Ent. Tidsk. 65:173- 
186. 

CELAENOPSINA TRAGARDH, 1938 

The Celaenopsina are characterized by a pair of lateral plates that 
developed on the ventral surface as anterior elongations of the ventral 
plate. These lateral plates have taken over the function of the epigynial 
plate and the latter is reduced or completely obliterated. With the re- 
duction of the epigynial plate there has been no development of a 



124 Ac urology 

median plate. The metasternal plates are no longer attached to the 
sternal plates i-iii but are separate and in some cases drastically reduced 
in size. The metasternal plates vary considerably within the group 
from the Celaenopsidae where they are large, uncovered, free, and 
possess both the typical seta and pore, to the condition found in Lo- 
bogynoides and other genera where they are small, covered, and lack 
the seta but possess two pores, and to the condition found in Lobo- 
gyniiim and other genera where they are fused with the sternal plate. 

Key to the Celaenopsina 

1. Metasternal plates partially or completely covered by lateral plates 2 
Metasternal plates not covered Celaenopsidae 

2. Anterior lateral lobes of ventral plate, lateral plates, not separated 
from ventral plate 3 

Lateral plates separated by suture from ventral plate; epigynial 
plate reduced and visible only at posterior junction of lateral 
plates Diplogyniidae 

3. Anal plate separate from ventral plate Euzerconidae 
Anal plate fused with ventral plate Schizogyniidae 

Diplogyniidae Tragardh, 1941 

Figure 93 

Diagnosis: Diplogyniids can be recognized by the presence of a pair 
of lateral plates that are triangular and hinged to the ventral plate 
laterally. These lateral plates meet in the midline anteriorly and are 
separated posteriorly by a small remnant of the epigynial plate. The 
metasternal plates are reduced and partially covered by the anterior 
margins of the lateral plates. Posterior to the lateral plates the ventral 
plate extends to the posterior end of the body and includes the anal 
plate. Lateral to the ventral plate there is a pair of metapodal plates 
that reach the posterior end. The male genital aperture is in front of 
the sternal plate and is flanked by a pair of presternal setae. Tragardh 
1950 has described fourteen new genera and split the family into five 
subfamilies. Four of the subfamilies are monotypic while the Diplo- 
gyniinae contains all of the other genera. A key to the subfamilies 
taken from Tragardh 1950 follows. 



Mesostigmata 



125 



Key to the Diplogyniidae 

1. Anal shield separated from ventral shield 
Anal shield not separated from ventral shield 



Neodiplogyniinae 
2 



Narrow band with minute spinules around margin 

Heterodiplogyniinae 

No such band 3 



3. Dorsal side densely clothed with minute setae 
Dorsal side not clothed with such setae 

4. Dorsal shield with row of hook-shaped bristles 
Dorsal shield without such bristles 




Trichdiplogyniinae 

4 

Meinertulinae 

Diplogyniinae 




Figure 93 Diplogyniiim tropica (Oudernans), 1927. Dorsal view of female 
(left) and ventral view of female (right). (After Oudemans 1928) 



Genera: 

1. Diplogynium Canestrini, 1889 (= Anoplocelaeno Berlese, 1910) 
Type. Diplogynium acuminatum Canestrini, 1889 

2. Antennocelaeno Berlese, 1903 

Type. Antennophorus />raw/?5/ Wasmann, 1902 



126 Acarology 

3. Brachy sternum Tragardh, 1950 

Type. Brachy sternum acuminatum Tragardh, 1950 

4. Cry ptometasternum Tragardh, 1950 

Type. Cry ptometasternum natalense Tragardh, 1950 

5. Diplogyniella Tragardh, 1950 

Type. Diplogyniella levinseniTv'i.gkxdVi, 1950 

6. Diplogyniopsis Tmgkrdh, 1950 

Type. Diplogyniopsis multidentata Tragardh, 1950 

7. Heterodiplogynium ^r'?kgkvd\\, \950 

Type. Heterodiplogynium vestitum Tragardh, 1950 

8. Lobogynioides Tragardh, 1950 

Type. Lobogynioides obtusum Tragardh, 1950 

9. Lobogynium Tragardh, 1950 

Type. Lobogynium rotundatum Tragardh, 1950 

10. M^gflc/irteroc/ie/fl Tragardh, 1 950 

Type. Megachaetochela warreni Tragardh, 1950 

11. Meinertula Tr'i.gkrdh, \950 

Type. Meinertula hamifera Tragardh, 1950 

12. Microdiplogynium Tragardh, 1950 

Type. Microdiplogynium reticulatum Tragardh, 1950 

13. Neodiplogynium^Y'2igkrd\\, \95Q 

Type. Neodiplogynium schubarti Tragardh, 1950 

14. Passalacarus Pearse and Wharton, 1936 

Type. Passalacarus sylvestris Pearse and Wharton, 1936 

15. Schizodiplogynium Tragardh, 1950 

Type. Schizodiplogynium capillatum Tragardh, 1950 

16. Trichodiplogynium Tragardh, 1950 

Type. Trichodiplogynium hirsutum Tragardh, 1950 

17. Tridiplogynium Tragardh, 1950 

Type. Tridiplogynium inexpectatum Tragardh, 1950 

Discussion: These large, handsome mites live as ectoparasites or 
commensals of large beetles and possibly other insects. They are of no 
known medical or economic importance. 

References: 

Pearse, A. S., et al. 1936. The ecology of Passalus cornutus Fabricius, a 

beetle that lives in rotting logs. Ecol. Monogr. 6:455-490. 
Tragardh, I. 1946. Outline of a new classification of the Mesostigmata 

(Acarina), based on comparative morphological data. K. Fysiogr. 

Sallsk. Handl. N. F. 57, Nr. 4:1-37. 
Tragardh, I. 1950. Studies on the Celaenopsidae, Diplogyniidae and Schizo- 

gyniidae. Arkiv. for Zoologi. Ser. 2, bd. 1, nr. 25:361-451. 



Mesostigmata 



127 



Euzerconidae Tragardh, 1938 

Figure 94 

Diagnosis: Euzerconids are similar to the Diplogyniidae but differ 
in that the lateral plates in the female are not separated by sutures 
from the ventral plate. The genital opening is therefore T-shaped. The 
anal plate is separate from the ventral plate. 




Figure 94 Euzercon latiis 
(Banks), 1909. Ventral view 
of female. 



Genus: 

Euzercon Berlese, 1888 

Type. Euzercon balzcnii Berlese, 1888 

Discussion: Members of this family live associated with beetles. They 
are world-wide in distribution but are of no known economic or medi- 
cal importance. 



Reference: 

Tragardh, I. 1946. Outline of a new classification of the Mesostigmata 
CAcarina), based on comparative morphological data. K. Fysiogr. 
Salisk. Handl. N. F. 57, nr. 4:1-37. 



128 



Acarology 



Celaenopsidae Berlese, 1892 

Figure 95 




Diagnosis: Celaenopsids are 
similar to the preceding fami- 
lies but their epigynial plate is 
obliterated by the lateral plates 
which are fused medially as 
well as to the ventral plate 
posteriorly. The metasternal 
plates are free, large, and rec- 
tangular in shape so that they 
appear to be genital valves. 
The genital opening, however, 
is posterior to the metasternal 
plates. 



Figure 95 Celaenopsis cuspidata 
(Kramer), 1876. Ventral view of 
female. (After Vitzthum 1940) 



Genera: 

1. Celaenopsis Berlese, 1886 (= Antennocelaeno Berlese, 1903) 

Type. Gamasus ciispidatus Kramer, 1876 

2. Ceratocelaenopsis Tragardh, 1950 

Type. Ceratocelaenopsis womersleyi Tragardh, 1950 

3. Dinocelaeno Oudemans, 1936 
Type. Gamasus gigas Duges, 1834 

4. Neocelaeno Berlese, 1910 

Type. Celaenopsis cryptodonata Berlese, 1901 

5. Pleuronectocelaeno Vitzthum, 1926 

Type. Celaenopsis {Pleuronectocelaeno) austriaca Vitzthum, 1926 

Discussion: As with other members of the suborder these mites are 
of no known economic or medical importance. 



References: 

Tragardh, I. 1946. Outline of a new classification of the Megostigmata 
(Acarina), based on comparative morphological data. K. Fysiogr. 
Sallsk. Hand!. N. F. 57, nr. 4:1-37. 



Mesostigmata 



129 



Tragardh, I. 1950. Studies on the Celaenopsidae, Diplogyniidae and Schi- 
zogyniidae. Arkiv. for Zoologi. Ser. 2, bd. 1, nr. 25:361-451. 

Schizogyniidae Tragardh, 1950 

Figure 96 

Diagnosis: This family is simi- 
lar to the Diplogyniidae but dif- 
fers in that both lateral and anal 
plates are fused with the ventral 
plates. The lateral plates are not 
fused in the midline as in the 
Celaenopsidae, however, and the 
sternal plate has a medial, cres- 
centic ridge. Males are not known. 




Figure 96 Schizogynium intermedium 
Tragardh, 1950. Ventral view of fe- 
male. (After Tragardh 1950) 



Genus: 

Schizogynium Tragardh, 1950 

Type. Schizogynium intermedium Tragardh, 1950 

Discussion: Tragardh 1950 considers the family to be intermediate 
between the Euzerconidae and the Diplogyniidae. Like the other mem- 
bers of the Celaenopsina species of this family are parasitic on beetles. 
The two known species are from Africa. 

Reference: 

Tragardh, I. 1950. Studies on the Celaenopsidae, Diplogyniidae and Schi- 
zogyniidae. Arkiv. for Zoologi. Ser. 2, bd. 1, nr. 25:361-451. 



FEDRIZZIINA TRAGARDH, 1937 

The females in this group are easily recognized because they have 
a median plate in addition to or in place of an epigynial plate. The 



130 Acarology 

median plate is in reality a sclerotized portion of the vaginal wall. The 
metasternal plates are fused with the sternal plate if these plates are 
present. Lateral shields are present or if absent they are secondarily 
reduced. The male genital opening is in the center of the sternal plate 
that is closed by a plate attached at its anterior margins. 

The Fedrizziina can be conveniently separated into seven families 
as indicated by the following key that is a modification of one pub- 
lished by Tragardh 1946. 

Key to the Fedrizziina 

1. Sternal and metasternal plates sclerotized 2 

Sternal and metasternal plates not sclerotized in female; their posi- 
tions indicated only by locations of sternal and metasternal setae 

Parantennulidae 

2. Lateral plates separate 3 

Lateral plates fused along midline; median plate reduced 

Syngynaspidae 

3. Median plate not fused to sternal plate 4 
Median plate fused to sternal plate Cercomegistidae 

4. Lateral plates completely sclerotized 5 

Lateral plates sclerotized only along median margin 

Antennophoridae 

5. Lateral plates triangular Paramegistidae 
Lateral plates linear Fedrizziidae 

Parantennulidae Willmann, 1940 

Figure 97 

Diagnosis: The dorsal plate is undivided, and the sternal and meta- 
sternal plates of the females are lacking. Tarsus i has no ambulacral 
apparatus, while tarsi ii, in, and iv have large caruncles and tiny claws. 
Chelicerae are chelate. 

Genera: 

1. Parantennulus BqyXqsq, \90A 

Type. Antennophorus scolopendranim Berlese, 1886 

2. Diplopodophilus WiWmsinn, 1940 

Type. Diplopodophilus antennophoroides Willmann, 1940 



Mesostigmata 131 

Discussion: These mites are found on myriapods and carabid beetles. 
They are of no known economic or medical importance. 





Figure 97 DipJopodophiliis antennophoroides Willmann, 1940. Ventral view 
of male (left) and female (right). (After Willmann 1941) 

Reference: 

Willmann, C. 1940. Neue Milben aus Hohlen der Balkanhalbinsel, ge- 
sammelt von Prof. Dr. K. Absolom, Brlinn. Zool. Anz. 130:209-218. 

. 1941. Die Acari der Hohlen der Balkanhalbinsel. Studien aus dem 

Gebiete der Allgemeinen Karstforschung, der Wissenschaftlichen 
Hohlenkunde, der Eiszeitforschung und den Nachbargebieten. Bio- 
logical serie nr. 8, pp. 1-80. 



Syngynaspidae Tragardh, 1938 

Figure 98 

Diagnosis: The lateral plates of the female 
are fused along the midline. The median plate 
is reduced. 



Figure 98 Syngynaspis tragdrdhi, n. sp. Ventral plates 
of female. (After Tragardh 1946) 




Genus: 



Syngynaspis 

Type. Syngynaspis tragdrdhi n. sp. 



132 Acarology 

Discussion: In 1937 Tragardh described a new genus Syngynaspis 
but failed to assign a specific name to the unique species on which the 
genus was based. This species described by Tragardh 1937 (Ark. 
Zool. 29 No. 11:6, Figure 9) is here named Syngynaspis trdgdrdhi. 
Tragardh erected the family Syngynaspidae for this form in 1938. 

Reference: 

Tragardh, I. 1937. Zur Systematik der Mesostigmata. Ark. Zool. 29 No. 
11:1-8. 



Cercomegistidae Tragardh, 1938 

Figure 99 



"^ 




Diagnosis: The median plate is 
fused with the sternal plates. The 
lateral plates are long and narrow 
and overlap the epigynial plate 
posteriorly. 



Figure 99 Cercomegistus sp. Ventral 
plates of female. (After Tragardh 
1937) 



Genera: 

1. Cercomegistus BqvXqsq, \9\A 

Type. Cercomegistus bruckianus Berlese, 1914 

2. Neo-Oudemansia 

Type. Neo-Oudemansia trdgdrdhi n. sp. 



Discussion: The genus Neo-Oudemansia was described by Tragardh 
in 1938 for a form that he failed to name. N. trdgdrdhi is here pro- 
posed for the species (Tragardh, L 1938. Ent. Tidsk. 3-4:137, Fig- 
ure 19). 



Mesostigmata 



133 



Reference: 

Tragardh, I. 1938. Further contributions towards the comparative mor- 
phology and classification of the Mesostigmata. Ent. Tidsk. 3-4:123- 
158. 



Antennophoridae Berlese, 1892 

Figure 100 



Diagnosis: Antennophorids are 
broadly oval in shape and have 
an undivided dorsal plate. Tarsus 
I lacks an ambulacral apparatus, 
while tarsi ii, iii, and iv have 
pretarsi and caruncles and at 
times weak claws. The median 
plate is a transverse, strongly 
sclerotized bar. The lateral plates 
are sclerotized medially, and the 
epigynial plate is fused with the 
ventral plate. 

Genera and subgenera: 




Figure 100 Antennophoriis foreli Ber- 
lese, 1904. Ventral view of female. 
(After Berlese 1904) 



1. 



4. 



5. 



Antennophorus Haller, 1877 

Type. Antennophorus uhlmanni Haller, 1877 (not Jannet, 1897) 

Antennurella Berlese, 1904 (= Eufedrizzia Sellnick, 1938) 

Type. Antennurella trouessarti Berlese, 1904 

Celaenopsoides Gunther, 1942 (doubtful) 

Type. Celaenopsoides buloloensis Gunther, 1942 

Celaenosthanus Vitzthum, 1930 

Type. Celaenosthanus trigonophilus Vitzthum, 1930 

Messoracarus Silvestri, 1912 

a. Messoracarus s. str. 

Type. Messoracarus mirandus Silvestri, 1912 

b. Leptantennus Berlese, 1916 

Type. Messoracarus {Leptantennus) pendulipes Berlese, 1916 
Ophiomegistus Banks, 1914 
Type. Ophiomegistus luzonensis Banks, 1914 
Physalozercon Berlese, 1903 
Type. Antennophorus raff ray Wasmann, 1902 
Ptochares SiXwQsXv'i, 1910 
Type. Ptochares daveyii Silvestri, 1910 



134 Acarology 

Discussion: These mites are associated with insects and large myria- 
pods. They are of no known economic or medical importance. 

Rejerence: 

Tragardh, I. 1943. Further contributions towards the comparative mor- 
phology of the Mesostigmata (Acarina) the Antennophoridae and 
the Megisthanidae. Arkiv. for Zoologi. 34A. N:o 20:1-10. 



Paramegistidae Tragardh, 1946 

Figure 101 

Diagnosis: The lateral plates are well developed, and are hinged to 
or fused with the ventral plate. The median plate is separated into two 
lateral elements in the female. The male genital opening is posterior 
to the sternal plate. 





Figure 101 Micromegistus bakeri Tragardh, 1948. Ventral view of female 
(left) and male (right). (After Tragardh 1948) 



Genera and subgenera: 

1. Paramegistus TT'2igkv6h, \906 

Type. Paramegistus con f rater Tragardh, 1906 

2. Echinomegistus Berlese, 1903 

a. Echinomegistus s. str. 

Type. Antennophorus wheeler i Wasmann (in Berlese, 1903) 

b. Antennomegistus Berlese, 1904 

Type. Antennophorus caputcarabi Berlese, 1903 

3. M/crom^^/^/wi' Tragardh, 1 948 

Type. Micromegistus bakeri Tragardh, 1948 

4. Neomegistus Tragardh, 1906 

Type. Neomegistus iulidicola Tragardh, 1906 



Mesostigmata 135 

Discussion: Mites of this family are found associated with insects 
and myriapods. They are of no known economic or medical impor- 
tance. 

Rejerence: 

Tragardh, I. 1948. Description of Micromegistus, a new genus of the Para- 
megistidae, with notes on Neomegistus, Paramegistus and Echino- 
megistus (Acarina). Ent. Tidsk. 69:127-131. 



Fedrizziidae Tragardh, 1937 

Figure 102 



Diagnosis: Fedrizziids are flat, 
broadly oval, and have an undi- 
vided dorsal plate. Their legs are 
short, leg i being thinner than the 
others. Tarsi i without, tarsi ii, 
III, and IV with pretarsi, caruncles, 
and claws. Chelicerae are chelate 
with ornate extensions. The tec- 
tum is triangular with a median- 
pointed projection. In the females 
the median plate is very large, the 
lateral plates are linear, and the 
epigynial plate is absent. The 
genital opening of the males is in 
the posterior sternal plate. 




Figure 102 Fedrizzia strandv (Oude- 
mans), 1927. Ventral view of female. 
(After Oudemans 1928) 



Genera: 



1. Fedrizzia Canestrini, 1884 (= Toxopeusia Oudemans, 1927) 

Type. Fedrizzia grossipes Canestrini, 1884 (= Toxopeusia strandi 
Oudemans, 1927) 

2. Klinckowstroemia 

Type. Klinckowstroemia trdgdrdhi n. sp. 



Discussion: In 1938 Tragardh proposed the genus Klinckowstroemia 
for a form that he failed to assign a specific name. This form is the 
type of Klinckowstroemia and is here named K. trdgdrdhi (Tragardh, 
I. 1938. Ent. Tidsk. 59:133-134, Figure 14). Mites of this family 



136 Acarology 

live associated with insects and myriapods and are of no known eco- 
nomic importance. 

Reference: 

Tragardh, I. 1946. Outlines of a new classification of the Mesostigmata 
(Acarina). K. Fysiogr. Sallsk. Handl. N. F. 57 No. 4:1-37. 



CHAPTER IV 



The Suborder Ixodides Leach, 1815 



THE Ixodides or ticks are all parasitic. Ticks as well as being simi- 
lar in habits also have many morphological features in common, 
such as a piercing hypostome with recurved teeth, chelicerae with lat- 
eral teeth on the movable digits, a pitlike sensory organ on tarsus i 
(Haller's organ), large size, and lateral stigmata without sinuous peri- 
tremes. Although ticks are similar to mesostigmatid mites there is no 
group of species intermediate between the two. It therefore seems 
desirable to consider the ticks as a separate suborder. 

Vitzthum 1941 divides the Ixodides into three subgroups each of 
which is represented by a single family. Rather than introduce group 
names, these will be ignored. 

No special discussion of the morphology of ticks will be needed for 
the understanding of the key to families. 

Key to the Ixodides 

1. Scutum present in all stages 2 
Scutum absent in all stages Argasidae 

2. Palpal tarsus terminal in position; scutum similar in texture to 
unmodified integument in females Nuttalliellidae 

Palpal tarsus imbedded in ventral apex of tibia; scutum of differ- 
ent texture than unmodified integument Ixodidae 

Argasidae G. Canes trini, 1890 

Figure 103 

Diagnosis (from Cooley and Kohls 1944) : The argasids are non- 
scutate Ixodides with slight sexual dimorphism. Both adults and 

137 



138 Acarology 

nymphs have a leathery, wrinkled, granulated integument, which is 
either mammilated or has tubercles. The capitulum in the adults and 
nymphs is either subterminal or distant from the anterior margin; in 
larvae it is subterminal or terminal. In depleted adults and nymphs 
especially, the capitulum is in a more or less marked depression (cam- 
erostome). Articulations of the palpi of all stages are free (never 





Figure 103 Antricola coprophiliis (Mcintosh), 1935. Ventral view of female 
(left) and Argas persicus (Oken), 1818. Dorsal view of female (right). (After 
Cooley and Kohls 1944) 

fused). Porose areas are absent in both sexes. When present the eyes 
are placed on the supracoxal folds. Spiracles in adults and nymphs 
are usually placed anterior to coxae iv. Pulvilli are usually rudimen- 
tary or absent in adults and nymphs but sometimes well developed 
(functional) in larvae. Nymphal stages are plural and the number 
variable. 

Genera: 

1. Argas Latreille, 1795 

Type. A earns refiexiis Fabricius, 1794 

2. Antricola Cooley and Kohls, 1942 

Type. Ornithodoros coprophilus Mcintosh, 1935 

3. Ornithodoros Koch, 1844 

Type. Argas savignyi Audouin, 1826 

4. Otobius Banks, 1912 

Type. Argas megnini Duges, 1884 

Discussion: The Argasidae are world-wide in distribution and occur 
on a wide variety of hosts. Snakes, turtles, many birds, and at least 



Ixodides 139 

eight orders of mammals are known to be attacked. Typically the ticks 
feed intermittently after the habit of bed bugs. Eggs are laid a few at 
a time. The larvae hatch and feed on the host for an extended period. 
They then detach and molt into nymphs. Nymphs usually require only 
an hour or two for feeding. After they have fed they leave the host and 
molt again into the second nymphal stage. Following another short 
meal the nymph is again ready to transform and eventually males and 
females are produced. Males can be distinguished from females in 
many cases only by slight differences in the genital openings. The male 
opening is usually slightly smaller and more arcuate. Omithodoros 
moubata and O. savignyi have larvae that do not feed and the first 
nymphs are the primary active stage in the life cycle. Otobius megnini, 
on the other hand, does not feed in the adult stage, and these adults 
do not have recurved teeth on the hypostome. 

Many argasid ticks frequent the burrows, nests, or homes of their 
hosts, where they feed intermittently. Ornithodoros talaje, for ex- 
ample, lives in the crevices of houses in southern Mexico, while O. 
moubata and Argas persicus are domestic pests in Africa and Persia 
respectively. Recently several new species of argasids have been de- 
scribed from bats in North and Central Americas. Cooley and Kohls 
1944 state: "There are likely still others that infest bats in the United 
States and probably in Mexico and Central America." It is not sur- 
prising to find argasids on bats since they are notorious for their 
homing instincts. 

Argasid ticks are of considerable economic and medical importance. 
Argas persicus is not only a bothersome domestic pest in parts of its 
range, but it also infests poultry all over the world, causing much dam- 
age by its bites. Not only are the bites injurious but also A. persicus 
transmits a spirochaetal disease to fowls. Cattle are susceptible to the 
spinose ear tick and deaths of cattle have been ascribed to this tick. 
Many species bite man and their bites can be extremely painful. Cooley 
and Kohls 1944 report the following species as attacking man in North 
America: A. persicus, Otobius megnini, Ornithodoros coriaceus, O. 
hermsi, O. nicollei, O. parkeri, O. rudis, O. stageri, O. talaje, and O. 
turicata. The spirochaets of relapsing fever Borrelia spp. are carried to 
man by at least eleven different species of Ornithodoros. O. parkeri 
has been demonstrated to carry tularemia experimentally. Rocky 
Mountain spotted fever, and American fever have been transmitted 
experimentally by argasids. 



140 



Acarology 



References: 

Cooley, R. A. and Glen M. Kohls. 1944. The Argasidae of North America, 

Central America and Cuba. Am. Midland Naturalist. Mongr. vi + 

152. 
Nuttal, G. H. F., C. Warburton, W. F. Cooper, and L. E. Robinson. 1908. 

Ticks. A monograph of the Ixodidae, Part I, The Argasidae, 1-104, 

Cambridge Univ. Press. 



Nuttalliellidae Schulze, 1935 

Figure 104 




Diagnosis: This family is inter- 
mediate between the Argasidae 
and Ixodidae. The scutum is not 
heavily sclerotized and is similar 
in appearance to the leathery in- 
tegument that covers the entire 
body. The integument has papillae 
similar to those found in the 
Argasidae. The palpi have freely 
movable segments, but there is a 
groove on the inner side of the 
second segment. The gnathosoma 
is anterior and visible from above 
as in the Ixodidae. 



Figure 104 Nuttalliella namaqua Bed- 
ford, 1931. Dorsal view of female. 
(After Bedford 1931) 



Genus: 

Nuttalliella Bedford, 1931 

Type. Nuttalliella namaqua Bedford, 1931 

Discussion: The type specimen was found under a stone in Little 
Namaqualand, Africa. It is not known to be of any economic or medi- 
cal importance. 



Ixodides 14 J 

Reference: 

Bedford, G. A. H. 1931. NuttalUella namaqua, a new genus and species 
of tick. Parasitol. 23:230-232 + PI. X. 

Ixodidae Murray, 1877 

Figure 105 

Diagnosis: The bodies of this family are oval and the gnathosoma 
is anterior and visible from above. The scutum of the males extends 
to the posterior margin, while that of the females is restricted to the 
propodosoma. Both the larvae and the nymphs have scuta similar to 




Figure 105 Dermacentor variabilis (Say), 
Cooley 1938) 



1821. Dorsal view of female. (After 



the females. Eyes may be present or absent. The larvae have two pairs 
of ventral stigmata lateral to the legs. The nymphs and adults have a 
single pair of spiracular plates. The terminal segment of the palps is 
reduced and inserted ventrally on the penultimate segment. Segments 
of palps are not freely movable. Porose areas are present on the base 
of the gnathosoma in the females. 

The Ixodidae can be divided into three subfamilies by use of the 
following key : 

Key to the Ixodidae 

1. Anal grooves do not surround anus anteriorly; ventral surface of 
males not almost completely covered by series of plates % 



142 Acarology 

Anal grooves surround anus anteriorly; ventral surface of males 
almost completely covered by series of plates Ixodinae 

2. Ventral surface of male without plates; scutum usually orna- 
mented Amblyomminae 

Ventral surface of male with four posterior plates, usually plain 

Rhipicephalinae 

Ixodinae Vitzthum, 1941 

Genera and subgenera: 

1. Ixodes Latreille, 1795 

a. Ixodes s. str. 

Type. Acarus riciniis Linnaeus, 1758 , 

b. Ceratixodes Neumann, 1902 

Type. Hyalomma piita Picard — Cambridge, 1876 

c. Endopalpiger Schulze, 1935 

Type. Endopalpiger luxiiriosus Schulze, 1935 

d. Eschatocephaliis v. Frauenfeld, 1853 

Type. Ixodes vespertilionis Koch, 1844 (= Eschatocephaliis gra- 
cilipes V. Frauenfeld, 1853) 

e. Exopalpiger Schulze, 1935 

Type. Ixodes priscicoUaris Schulze, 1932 

f. Lepidixodes Schulze, 1935 

Type. Eschatocephaliis kopsteini Oudemans, 1925 

g. Sternalixodes Schulze, 1935 

Type. Ixodes cordifer Neumann, 1908 

Amblyomminae Neumann, 1911 

Genera and subgenera: 

1. Amblyomma Koch, 1844 {— Haemalastor Koch, 1844) 
Type. Acarus cajennensis Fabricius, 1787 

2. Alloceraea Schulze, 1918 

Type. Haemaphy salts inermis Birula, 1895 

3. Amhlycentor Schulze, 1932 

a. Amhlycentor s. str. 

Type. Ixodes rhinocerinus Denny, 1 843 

b. Piincticentor Schulze, 1933 

Type. Dermacentor cricumgiittatiis Neumann, 1897 

4. Anocentor Sc\\\x\zQ, 1937 (= Otocentor Coo\Qy, 1938) 

Type. Dermacentor nitens Neumann, 1897 (= Anocentor columbi- 
anus Schulze, 1937) 



Ixodides 143 



5. Aponomma Neumann, 1899 
Type. Ixodes gervaisi Lucas, 1 847 

6. Dennacentor Koch, 1844 

a. Dermacentor s. str. 

Type. Acarus reticulatus Fabricius, 1794 

b. Dermacentorites OlenQW, 1931 

Type. Cynorhaestes pictus Hermann, 1804 

7. Haemaphysalis Koch, \%AA 

Type. Haemaphy salts concinna Koch, 1844 

8. Indocentor Schulze, 1933 

Type. Dermacentor auratus Supino, 1897 



Rhipicephalinae Vitzthum, 1941 

Genera and subgenera: 

1. Rhipicephalus Koch, 1844 

a. Rhipicephalus s. str. 

Type. Ixodes sanguineus Latreille, 1 806 

b. Pterygodes Neumann, 1913 

Type. Rhipicephalus {Pterygodes) fulvus Neumann, 1913 

2. Boophilus CuvXice, 189\ 

a. Boophilus s. str. 

Type. Ixodes annulatus Say, 1821 (= Ixodes bovis Riley, 1867) 

b. Palpoboophilus Minning, 1934 

Type. Rhipicephalus decoloratus Koch, 1844. 

c. Uroboophilus Minning, 1934 

Type. Uroboophilus sharifi Minning, 1934 

3. Cosmiomma Schulze, 1919 

Type. Ixodes hippopotamensis Denny, 1843 

4. Hyalomma Koch, 1844 

a. Hyalomma s. str. 

Type. Acarus aegyptius Linnaeus, 1758 

b. Hyalommasta Schulze, 1930 

Type. Hyalomma syriacum Koch? 1844 

c. Hyalommina Schulze, 1919 

Type. Hyalomma rhipicephaloides Neumann, 1901 

5. Margaropus Karsch, 1879 

Type. Margaropus winthemi Karsch, 1879 

6. Nosomma Schulze, 1919 

Type. Hyalomma monstrosum Nuttall and Warburton, 1908 

7. Rhipicentor Nuttall and Warburton, 1908 

Type. Rhipicentor bicornis Nuttall and Warburton, 1908 



144 Acarology 

Discussion: Ticks in general, and ixodids in particular, are perhaps 
the best known of any of the Acarina. That this is so is not surprising 
since they are also the largest of the Acarina, parasites of man and his 
domestic animals as well as wild animals, and the vectors of many 
serious diseases. Despite the broad knowledge of ticks there is con- 
siderable disagreement among specialists on the generic names to be 
applied to them. The arrangement of the genera listed here is taken 
largely from Vitzthum 1941, who in turn has followed Schulze. Other 
specialists prefer to reduce many of Schulze's names to synonymy. 

The life cycle of ixodids is fairly simple. The female deposits a large 
egg-mass on the ground. Six-legged larvae hatch from the eggs. The 
larvae then feed on a suitable host. After the larvae become engorged 
with blood they molt and become nymphs. The nymphs have eight 
legs and are similar in appearance to the adult female. However, they 
are smaller and lack a genital opening. Nymphs engorge and molt to 
produce adult males and females. Both males and females feed. The 
male is encased in a fairly nonelastic integument and so does not in- 
crease greatly in size after feeding. The female, on the other hand, 
swells greatly during engorgement. After copulation and engorgement 
the female is ready for oviposition. 

This general life cycle exhibits many modifications in different de- 
tails. The majority of ixodids usually parasitize different hosts in the 
immature and mature stages. For example, Dermacentor venustus Neu- 
mann i= D. andersoni Stiles) has been reported in the larval and 
nymphal stages from small mammals, while as an adult it has been 
taken from sheep, goats, man, etc. D. venustus drops to the ground 
in order to molt or lay eggs, so that each tick must find at least three 
individual hosts if it is to complete its life cycle. Boophilus annulatus 
(Say) on the other hand attaches itself to cattle in the larval stage and 
does not leave its host until it is ready to lay its eggs. Nuttall 1911 
indicates that Ixodes rincinus (Linnaeus) can complete its life cycle 
in as little as one hundred and seventy days, but that under unfavor- 
able conditions it may take two or three years. 

Ixodids are of great economic and medical importance. Heavy in- 
festation with ixodid ticks can cause anemia in domestic animals. 
Several noxious diseases are carried to animals by ticks such as Texas 
cattle fever to bovines by Boophilus annulatus (Say). Ixodids may 
cause paralysis in man by their bites and they also have been incrimi- 
nated in transmitting the following diseases to man: Rocky Mountain 
and other spotted fevers of the Americas, fievre boutonneuse, Kenya 



Ixodides 145 

typhus, South African tick-bite fever, the fevers, tularemia, and 
possibly others (Mackie, Hunter, and Worth 1945). Detailed accounts 
of the role of ixodids as vectors of disease are to be found in most 
books on parasitology and tropical medicine. 

References: 

Cooley, R. A. 1938. The genera Dermacentor and Otocentor (Ixodidae) 

in the United States, with studies in variation. Nat. Inst. Health Bull. 

No. 171:1-85 + Pis. 
. 1946. The genera Boophilus, Rhipicephalus, and Haemaphysalis 

(loxodidae) of the New World. Nat. Inst. Health Bull. 187: 54 + hi. 
Cooley, R. A. and G. M. Kohls. 1945. The genus Ixodes in North Amer- 
ica. Nat. Inst. Health Bull. 184:246 + iii. 
Douglas, J. R. 1943. The internal anatomy of Dermacentor andersoni 

Stiles. Univ. of Calif. Publ. in Ent. 7(10) :207-272 + Pis. 
Fielding, J. W. 1926. Australasian Ticks. Dept. of Health Commonwealth 

of Australia Service Publ. (Trop. Div.) No. 9:1-114. 
Neumann, L. G. 1911. Ixodidae. Das Tierreich. Acarina. 26 Lieferung 

1-169. 
Nuttall, G. H. F. and C. Warburton. 1911. Ticks. A monograph of the 

Ixodidea, Part II, The Ixodidae. 105-348. Cambridge Univ. Press. 
and . 1915. Ticks. A monograph of the Ixodoidea, Part III, 

The genus Haemaphysalis. 349-550 + Pis. Cambridge Univ. Press. 
Robinson, L. E. 1926. Ticks: A monograph of the Ixodoidea, Part IV, The 

Genus Amblyomma. 1-302 + Pis. Cambridge Univ. Press. 



CHAPTER V 



M 



The Suborder Tromhidiformes Renter^ 1909 



THESE mites possess a pair of stigmata on or near the gnathosoma, 
although occasionally the stigmata may be absent. The palpi are 
usually free and highly developed, either as pincer-like clasping organs 
or sensory organs. The chelicerae are usually modified for piercing, 
although in the primitive, predaceous families a few have opposed 
chelae which are apparently for seizing prey. They may or may not 
possess genital suckers, but anal suckers are never present. 

The Tromhidiformes are here divided into three groups, the Tetra- 
podili, the Tarsonemini, and the Prostigmata. The Tetrapodili contains 
the tiny, wormlike, plant-feeding Eriophyidae which possess only two 
pairs of legs in all stages and which lack a respiratory system. The 
Tarsonemini includes the small plant and arthropod parasites with 
minute mouth parts, small appressed palps, tiny needle-like chelic- 
erae, and with the stigma behind the pedipalps in the female and 
lacking in the male; many in this group do not possess the full number 
of legs and appear to be quite degenerate. The Prostigmata is com- 
posed of those mites with the stigma opening at the base of the che- 
licerae; they are usually large mites with large, free-moving mouth 
parts, in many cases the palps being highly developed as feelers or 
grasping organs. The chelicerae, although perhaps modified, usually 
are large and well developed for piercing or grasping. In the Tarso- 
nemini we have a single more or less homogeneous group, but in the 
Prostigmata we find many groups, such as those with a thumb-claw 
complex on the palps (Trombidiidae), those with very simple palps 
(Rhagidiidae), those with piercing, needle-like chelicerae (Tetrany- 
chidae), or those with grasping or crushing mouth parts (Rhagi- 
diidae). These, with their related families, perhaps form the basis for 

146 



Trombidiformes 147 

superfamilies, but since this grouping is still in the formative stage no 
attempt is here made to present categories other than families. 

Key to the Trombidiformes 

1. Body of normal shape, not wormlike (except in Demodicidae); 
with normal four pairs of legs (except certain cases in Podapo- 
lipodidae and Phytoptipalpidae) ; with or without well-developed 
gnathosoma; with respiratory system 2 

Body wormlike, annulate; with only two pairs of anteriorly placed 
legs; no respiratory system; gnathosoma greatly reduced; palpi 
minute, lying close to rostrum; chelicerae stylet-like; minute plant- 
feeding mites Tetrapodili (Eriophyidae) 

2. Chelicerae tiny, stylet-like; palpi minute, lying close to rostrum; 
gnathosoma as a whole greatly reduced, inconspicuous; tiny mites 
with or without usual number of legs; stigma of 2 behind max- 
illae; i without stigma or tracheae Tarsonemini 

Chelicerae much larger, easily seen; palpi not minute nor lying 
close to rostrum (except the wormlike Demodicidae which has 
four pairs of legs); gnathosoma usually conspicuous; as a whole, 
large mites with four pairs of legs (except in Phytoptipalpidae 
where one genus possesses only three pairs of legs); stigma open- 
ing at base of chelicerae {Demodex without stigma or tracheae) 

Prostigmata 

TETRAPODILI BREMI, 1872 

These are minute, w^ormlike, plant-feeding mites measuring up to 
0.20 mm. in length. They possess two pairs of legs anteriorly which 
lack tarsal claws but which have a "featherclaw." The body is ringed 
and the genital opening is located just behind the legs and is covered 
by a transverse plate. There are no eyes, no heart, no excretory sys- 
tem, and no respiratory system. Only a few setae are present. The 
Tetrapodili contains only a single family, the Eriophyidae. 

Eriophyidae Nalepa, 1898 

Figure 106 

Diagnosis: The eriophyids are minute, wormlike mites whose propo- 
dosoma is shieldlike and has distinctive, specific patterns. The hys- 
terosoma is elongated and annulate. These mites do not possess a 
respiratory system. Two pairs of anterior legs are present in all stages 



J 48 Acarology 

and all tarsi have rayed claws. The genitalia are situated on the ante- 
rior, ventral portion of the body just behind the legs and the genital 
plate is a transverse rather than a longitudinal slit. Palpi are short and 
simple. The chelicerae are short and stylet-like for piercing. The anal 
opening is on the posterior of the body. These mites are either free- 
living on plants or gall makers. Vitzthum divides this group into the 

Eriophyidae and Phyllocoptidae, 
but Keifer's single-family arrange- 
ment is followed here. 

Although the Eriophyidae have 
been separated from the prostig- 
matic mites and placed in a sepa- 
rate group, the Tetrapodili, their 
relationship to the normal eight- 
legged mites can be demonstrated. 
In certain of the normal groups 
some genera begin to lose a pair 
of legs, as in the Podapolipodidae 
which are parasitic on insects. 
This is not surprising since the 
mode of life in this family would 
tend towards a parasitic baglike 
mite. In the Phytoptipalpidae, 
which are plant feeders and are 
closely related to the Tetranychi- 
dae, one genus, Phytoptipalpus, 
possesses only three pairs of legs. 
In this same family, Tenuipalpus 
eriophyoides Baker (nymph), al- 
though possessing four pairs of legs, is very elongated and annulate, 
greatly resembling an eriophyid mite. The transverse genital plates 
also indicate the relationship of the Eriophyidae to the Phytoptipalpi- 
dae, since these two families are the only ones which possess this type of 
organ, other genital openings being longitudinal. The genitalia of the 
Eriophyidae is located just behind the legs, far anteriorly, while that of 
the Phytoptipalpidae is at the rear of the body. This difference is not as 
significant as may be presumed since there probably has been a coalesc- 
ing of body segments posteriorly in the phytoptipalpid type which gives 
the appearance of having the genitalia on the extreme end rather than 
in a more or less normal position. The rayed tarsal appendage of the 




Figure 106 Oxypleiirites ciesciilifoliac 
Keifer. Egg, two nymphal, protogyne, 
and deutogyne stages. (After Keifer 
1942) 



Trombidiformes 149 

eriophyids is somewhat similar to that of the genus DoUchotetranychiis 
in the family Phytoptipalpidae. The stylet-like chelicerae and the gen- 
eral biology of the group also indicate a common ancestry with the 
plant-feeding Tetranychidae and Phytoptipalpidae. 

Key to the Eriophyidae 

(from Keifer) 

1. Three or four setiferous tubercles on shield; rear pair of tuber- 
cles always bearing setae that point forward; anterior pair of sub- 
dorsal abdominal setae present or absent; foretibia usually with 
lateral spur; hind patellar seta often laterally placed; female 
coverflap smooth; female genital glands elliptical or elongate, aris- 
ing from ducts that project forward and then recurve laterally 2 

One pair of setiferous tubercles on cephalothoracic shield, or 
these absent; no subdorsal abdominal setae; no lateral spur on 
foretibia; hind patellar seta always arising from above; female 
genital coverflap variously sculptured or smooth; female genital 
glands usually subcircular and on short lateral or diagonally, pos- 
teriorly directed ducts originating from rear of genital opening 3 

2. Shield with no anterior lobe over rostrum; abdomen wormlike 
with rings similar dorsoventrally Phytoptinae 

Shield with anterior lobe over rostrum which is sometimes very 
short; abdomen divided laterally into broader tergites, and more 
numerous narrower sternites Sierraphytoptinae 

3. Shield never with lobe overhanging rostrum; abdomen wormlike, 
with rings similar above and below, at least anteriorly; when ros- 
trum large, not set at right angles to body and with evenly curved 
chelicerae Eriophyinae 

Shield usually with anterior lobe over rostrum; abdomen most 
often divided laterally into broader tergites and narrower ster- 
nites; or with large tapering rostrum, set at right angles to body, 
and with large chelicerae abruptly downcurved in from rostrum 
base Phyllocoptinae 

Phytoptinae Keifer, 1944 

Genera: 

1. Phytoptus DuJardin, 1851 

Type. Eriophyes avellanae Nalepa, 1889 

2. Setoptus Keifer, 1944 

Type. "Platy phytoptus" jonesi Keifer, 1938 



150 Acarology 



Sierraphytoptinae Keifer, 1944 
( = Mackiellinae Keifer, 1946) 
Genera: 

1. Sierraphytoptiis Keifer, 1939 

Type. Sierraphytoptiis alnivagrans Keifer, 1939 

2. Aiistracus Keifer, 1944 

Type. Aiistracus havrylenkonis Keifer, 1944 

3. Mackiella Keifer, 1939 

Type. Mackiella phoenicis Keifer, 1939 

4. Nalepella Keifer, 1944 

Type. Phyllocoptes triceras Borner, 1906 

Eriophyinae Nalepa, 1898 
Genera: 

1. Eriophyes von Siebold, 1850 
Type. Eriophyes vitis (Pgst.), 1857 

2. Aceria Keifer, 1944 

Type. Eriophyes tulipae Keifer, 1938 

3. C^c/^oJecfe5 Nalepa, 1917 

Type. Cecidodectes euzomis Nalepa, 1917 

4. C^c/Jo/7/zye5 Nalepa, 1887 

Type. Phytoptus galii Karpelles, 1884 

5. Cymoptiis Keifer, 1946 

Type. Cymoptus spiniventris Keifer, 1946 

6. Monochetus Nalepa, 1898 (= Monaulax Nalepa, 1892 nom. prae- 

occ.) 
Type. Monaulax sulcatus Nalepa, 1892 

7. Novophytoptus Roivainen, 1947 

Type. Novophytoptus rostratae Roivainen, 1947 

8. Paraphytophus^dAQ^ii, \^96 

Type. Paraphytophus paradoxus Nalepa, 1896 

9. Phytoptochetus Nalepa, 1917 

Type. Phytoptochetus tristichus Nalepa, 1917 
10. Trichostigma Gerber, 1902 

Type. Trichostigma crodii Gerber, 1902 

Phyllocoptinae Nalepa, 1898 
Genera: 

1. Phyllocoptes Nsilepa, \SS9 

Type. Phyllocoptes carpini Nalepa, 1887 



Trombidiformes 151 

2. Abacanis Keifer, 1944 

Type. Calepitrimcnis acalyptus Keifer, 1939 

3. Abacoptes Keifer, 1939 

Type. Abacoptes platynus Keifer, 1939 

4. Acamitui Keifer, 1944 

Type. Calepitrinierus noliiuie Keifer, 1939 

5. Acaphylla Keifer, 1943 

Type. Acaphylla stcinweidcni Keifer, 1943 

6. Acarelliptus Keifer, 1940 

Type. Acarelliptus coccifonnis Keifer, 1940 

7. Acaricalus Keifer, 1940 

Type. Acaricalus segundus Keifer, 1940 

8. .4/zr/jocop/^A' Nalepa, 1892 

Type. Phyllocoptes loricatus Nalepa, 1889 

9. Calacarus Keifer, 1940 

Type. Calacarus pulviferus Keifer, 1940 

10. Calepitrinierus KQifer, 1938 

Type. Calepitrinierus cariniferus Keifer, 1938 

11. Crt/z^^y/opm^ Keifer, 1938 

Type. Caliphytoptus quercilobatae Keifer, 1938 

12. Crt//y/7r/-c»/i/5 Nalepa, 1894 

Type. Callyntrotus schlectendali Nalepa, 1894 

13. Caroloptes Keifer, 1940 

Type. Caroloptes fagivagrans Keifer, 1940 

14. Coptophylla Keifer, 1944 

Type. Phyllocoptes lamimani Keifer, 1939 

15. Cr//7c/cc/n/5 Keifer, 1 943 

Type. Cupacarus cuprifestor Keifer, 1943 

16. Diptilomiopus Nalepa, 1916 

Type. Diptilomiopus javanicus 'Nix\epii, 1916 

17. Epitrinierus Nalepa, 1898 

Type. Epitrimerus gemmicola Nalepa, 1 898 

18. Ganinuiphytoptus Keifer, 1939 

Type. Gammaphytoptus camphorae Keifer, 1939 

19. 0.v>'/7/t^i(r/7£'.y Nalepa, 1891 

Type. Acanthonotus heptacanthus Nalepa, 1889, desg. by Keifer, 
1938 
(Tegonotus trouessarti Nalepa, 1890, desg. by Vitzthum 1943) 

20. Phyllocoptruta Keifer, 1938 

Type. Typhlodronuis oleivorus Ashmead, 1879 

21. Phyllocoptychesn\x\ep2i, 1922 

Type. Phyllocoptyches gallicolus Nalepa, 1922 

22. Platyphytoptus Keifer, 1938 

Type. Platyphytoptus sabinianae Keifer, 1938 



J 52 Acarology 

23. Qimdracus Keifer, 1944 

Type. Quadrcicus urticae Keifer, 1944 

24. Rhyncaphytoptus Keifer, 1939 

Type. Rhyncaphytoptus ficifolicie Keifer, 1939 

25. 7^^o/7omjy Nalepa, 1890 

Type. Tegonotus fastigatus Nalepa, 1890 

26. Tetra Keifer, 1944 

Type. "Phyllocoptruta" concava Keifer, 1939 

27. Thafnnacus Keif QT, \944 

Type. Phyllocoptes rhamnicola Keifer, 1938 

28. Tumescoptes Keifer, 1939 

Type. Tumescoptes trachycarpi Keifer, 1939 

29. Vasates Shimer, 1869 

Type. Vasates quadripedes Shimer, 1869 

Unassigned genus: 

Flexipalpus Schcuten, 1857 

Type. Flexipalpus tiliae Scheuten, 1857 

Discussion: Not until Keifer's 1942 work on the alternation of gen- 
erations in the buckeye rust mite {Oxypleurites aesculijoliae Keifer), 
was the life cycle of certain of the eriophyid mites fully understood. 
Yothers et al. 1930 had studied the citrus rust mite and Baker 1939 
the fig mite, but both species belong to those having a simple life cycle 
without alternation of generations. Keifer's study on the buckeye rust 
mite has also solved the problem of the pear leaf rust mite, Epitri- 
merus pirijoliae Keifer. 

One female of Oxypleurites aesculijoliae resembles the male and is 
called the protogyne. The other female of this species is morphologi- 
cally different from the primogyne, or primary type, and has no male 
counterpart. This Keifer calls the deutogyne. Originally, owing to dif- 
ferences in striation, the two forms had been described as different 
species in different genera [Phyllocoptes aesculifoliae (protogyne) and 
Oxypleurites neocarinatus (deutogyne)]. The Oxypleurite female, or 
protogynes, when reared, produced both forms of females. Deutogynes 
when reared laid eggs which gave birth to egg-laying protogynes. 

The following life history of the buckeye rust mite is taken from 
Keifer 1942. 

The deutogynes become active in late winter, leave their hibernating quar- 
ters on the twigs and when the buds swell in February, penetrate beneath 
the outer scales; there they feed on the green tissue of the inner scales. 



Trombidiformes 153 

With the development of the early spring leaves, the deutogynes lay eggs 
which hatch into nymphs producing primary mites on the leaves. These 
primaries soon begin active reproduction of additional primary mites. Be- 
ginning about the last of April or early May, new deutogynes appear 
among the primary types and when full fed, these deutogynes travel down 
the stems 6 inches or more. There they crawl into crevices or other shelters 
on the previous season's wood. Thus deutogynes are leaving the leaves 
through May and until leaf drop in the middle of July. The primary mites 
are confined to the leaves and green tissue and perish with it, although 
reproduction has largely ceased by early July. The mites prefer the under- 
side of the leaves, but usually there is such a high population that both 
surfaces are inhabited and considerable leaf "rusting" results. Once the 
deutogynes attain a suitable crevice they become dormant and partially 
dry out in late summer. However, winter rains and frost reverse this proc- 
ess and recondition the deutogynes for activity the following spring. There 
is a high mortality among the deutogynes, principally because of crevice 
limitation. 

While the spring progeny of the buckeye Oxypleurites deutogynes were 
not critically examined, it was noted that the first series of primary types 
contained egg-laying females, indicating either predormancy fertilization 
of the deutogynes or a deuterotokous reproductive capacity. 

Putman, 1939 (Seventh Ann. Rpt. Ent. Soc. Ont. p. 33), working with 
Phyllocoptes fockeui in Canada, has described what is clearly discerned to 
be a functional deutogyne, and states that both males and females hatch 
from eggs laid by overwintering females. He considers that these overwin- 
tering females (deutogynes) may have been fertilized before hibernation, 
since he showed that ordinary unfertilized females (protogyne) produce 
only males. Putman further noted that the production of "hibernating 
forms" seemed correlated with foliage hardening, a speculation consistent 
in the main with observations on the buckeye mite. 

The fig mite, Aceria ficus (Cotte), which illustrates a simple life 
cycle, does not directly cause serious injury to the fig in California, as 
do some eriophyids to their hosts. The mites live in the bud scales, on 
the leaf surfaces, or inside the greerj figs. If the population is high 
enough individual bud scales are scarred and some immature leaves 
killed within the bud. The scarred or rusted condition is seldom no- 
ticed on the mature leaves. However, this rusty condition is quite no- 
ticeable within the fig where the usual damage is to the eye scales only. 
With a large population the scarring may penetrate the interior of the 
fig. It is thought that the smuts and molds of the figs {Aspergillus, 
Hormodendrum, Caldosporium, Rhizopus) obtain an early foothold 
on the necrotic areas caused by the feeding of the mites within the fig. 



154 Acarology 

The mites spend the winter within the terminal buds, the population 
varying from ten to several hundred per bud, with about 10 per cent 
of the buds infested. Reproduction takes place throughout the winter. 
In the spring when the leaf buds break open the mites infest both sur- 
faces of the leaves. The population reaches its peak in June and July 
Eggs are laid indiscriminately on upper and lower leaf surfaces of 
young, tender leaves, but the mites are usually found only on the lower 
surfaces of the mature leaves, probably because the lower surface is 
more succulent and is shaded from the sun. In cases of extremely 
heavy infestation the mites may be found on the dorsal leaf surface. 
First-crop figs are infested within two weeks after the fruit buds have 
pushed out into figs. About 90 per cent of this crop is infested. Second- 
crop figs are infested about eight days after being formed and nearly 
all the second crop is infested by the first of July. However, as the fig 
ripens and the eye scales loosen, the predaceous mites and thrips take 
their toll until in a ripe fig only a few mites are to be found. These 
mites which have found their way into the terminal buds throughout 
the summer carry over the population during the winter. As high as 
50 per cent of the buds examined during the summer have been in- 
fested. 

The following account of the importance of the eriophyids has been 
taken from Keifer 1946. 

The Eriophyid mites, variously known as gall mites, blister mites, rust 
mites, and bud mites, are the smallest animals bearing an exterior skeleton 
with which the agriculturist has to contend. They deform and russet leaves 
and fruit, blast buds, and if uncontrolled will frequently put their host 
plant out of production. 

Eriophyids exhibit a very intimate mite-host relationship, characterized 
by considerable host specificity. Gall formation of one kind or another is 
another aspect of this intimacy, but the majority depend on natural forma- 
tions on their hosts and cause no discernible injury. They remain in loca- 
tions where feeding and breeding can take place whenever temperature 
permits, with few exceptions. The exceptions are specialized aestivating 
forms which spend their quiescent period in dry bark crevices. 

In general there are two types of Eriophyids; the worm-like soft kinds 
that are gall mites or bud mites, and which do all their feeding and breed- 
ing under cover, and the rust mites, which are broader and chunkier, often 
rather flat, which have heavy back plates to protect them against the action 
of light and desiccation, and which feed and breed more or less on open- 
leaf surfaces. This latter type, with few exceptions, constitutes the rust 
mites, or leaf vagrants. 



PZaf^ / Damage to lemon blossoms, buds, and fruit caused by Aceria sheldoni 
(Ewing). (From A. M. Boyce, Insects and mites and their control, the Citrus 
Industry, Volume II, 1948. Courtesy of The University of California Press.) 



»i 




Trombidiformes 157 

The mite species which are of more or less economic importance in 
North America number about 50. Of these the pear leaf blister mite is 
perhaps the most generally known, and one of the most important, since 
it can put its host out of fruit production. 

The Eriophyid mites on grape lack greater importance than they have 
largely because grapes are so consistently sulfured for mildew. Neverthe- 
less there are two kinds of these mites known in North America, namely, 
the grape erineum mite, Eriophyes vitis (Pgst.), and the grape rust mite, 
Calepitrimenis vitis (Can.). The former species forms erineum patches 
on the under surface of the leaves and there seems to be a certain amount 
of varietal resistance to the activities of this mite shown by different kinds 
of grapes. For example, one kind of grape which is fairly well over-run 
with erineum patches has been observed to be interlocked with another 
variety of grape which had few or no erineum patches. 

The grape rust mite, which develops deutogynes in the fall, has received 
little attention in North America. 

On citrus, the rust mite, Phyllocoptruta oleivorus (Ashm.) is a pest of 
long standing in the warmest citrus-growing areas of the United States. 
This mite, which is on an evergreen host, winters on the leaves and pro- 
duces no specialized hibernating forms. 

In California, the most important citrus Eriophyid pest is the citrus bud 
mite, Aceria sheldoni (Ewing), which is to be found in practically all of 
the citrus-growing areas adjacent to the coast in Southern California. Se- 
verely damaged lemon trees show stunting and clustering of the young 
growth, and severe leaf and fruit malformation. These mites leave a char- 
acteristic brown condition in the buds in which they work. They may be 
found developing in large numbers under fruit buttons where they also 
leave a brown injury. 

The citrus bud mite also works on oranges and grapefruit and seems to 
have a general range through the Pacific citrus-growing areas. Very similar 
or identical populations damage citrus in such places as Hawaii, Australia 
and Java. 

Peach is infested by one Eriophyid, namely, the silver mite, Vasates 
cornutus (Banks). This mite winters around the lateral buds from 3 to 12 
inches below the terminals, in the form of deutogynes. In the early spring, 
these mites invade the tender growing tips, and at that time, if the host 
plant lacks leaf glands, or if the leaf glands are not operating properly 
(these produce a sticky secretion), the mites cause an unhealthy longitudi- 
nal rolling of the leaves and, in some cases, numerous fine yellow dots on 
the leaves. This injury is not to be confused with the silvering of the peach 
leaf, which silvering occurs after prolonged feeding during spring and 
summer. The mite feeds on both leaf surfaces and produces deutogynes 
only in response to the temperature drop in the fall. 



158 Acarology 

The plum nursery mite, Vasates fockeui (Nal. & Trt.), is found through- 
out the northern states and Canada. It severely damages young growth on 
plums which accounts for its common name. This mite is closely similar 
to the peach silver mite, no characters at the present time being available 
to indicate a structural distinction between the two. 

Filbert and currant suffer from the attacks of big-bud mites, Phytoptus 
avelkmae Nal., and Cecidophyes ribis Nal., respectively. The terminal buds 
on certain filbert varieties enlarge in the spring, and turn into galls never 
producing shoots. The filbert mite is unique in having two types of nymphs, 
a normal type developing in the big-buds, and a flattened nymph which 
spends the summer on the undersides of the leaves. 

The redberry mite on blackberries along the Pacific Coast, namely, 
Aceria essigi (Hassan), insures itself a breeding place in an unusual man- 
ner. Feeding in the developing berry by this mite causes either all of the 
drupelets, or the basal ones, to remain red and unripe. The berry thus 
hangs on the vine longer, and is unfit for eating. 

The Eriophyid with the most peculiar habitat, that has come to notice 
so far, is the onion or bulb Eriophyid, Aceria tulipae (K.). Liliaceous bulbs 
such as onion, garlic and tulip are attacked, the mites living between the 
bulb layers. Thus the mite lives underground, a habit not known to be 
possessed by any other species. The activities of Aceria tulipae cause the 
bulbs to shrink and dry out. These mites persist in storage. 

References: 

Baker, E. W. 1939. The fig mite, Eriophyes ficiis Cotte, and other mites of 
the fig tree, Ficus carica Linn. Bull. Calif. Dept. Agr. 28(4) : 266-275. 

Boyce, A. M., and R. B. Korsmeier. 1941. The citrus bud mite, Eriophyes 
sheldoni Ewing. J. Econ. Ent. 34(6) :745-756. 

Hodgkiss, H. E. 1930. The Eriophyidae of New York: IL The maple 
mites. N. Y. State Agr. Expt. Sta. Tech. Bull. 163. 

Keifer, H. H. 1938. Eriophyid studies. Bull. Calif. Dept. Agr. 27(2) : 181- 
206, and subsequent publications. 

. 1942. Eriophyid studies XIL Bull. Calif. Dept. Agr. 31 (3): 

117-129. 

. 1946. A review of North American economic eriophyid mites. 

J. Econ. Ent. 39(5) :563-570. 

Parrott, P. J., H. E. Hodgkiss, and W. S. Schoene. 1906. The apple and 
pear mites. N. Y. State Agr. Expt. Sta. Bull. 283. 

Yothers, W. W., and A. C. Mason. 1930. The citrus rust mite and its con- 
trol. U.S. Dept. Agr. Tech. Bull. 176. 



Trom b idiform es 159 

TARSONEMINI CANESTRINI AND FANZAGO, 

1877 

The females possess a tracheal system behind the pedipalps; the 
males perhaps may have a rudimentary stigma. The females usually 
have a pair of latero-ventral, keglike pseudostigmatic organs between 
coxae I and ii. The mouth parts are reduced. The two sexes are usually 
differentiated. 

Key to the Tarsonemini 

1. Both males and females with four pairs of legs 2 

Females with one to three pairs of legs; males with three, seldom 
four, pairs of legs Podapolipodidae 

2. Anterior dorsal body plate not forming a broad, rooflike covering 
over mite; leg iv not ending in many whiplike setae 3 

Anterior dorsal body plate forming broad rooflike covering over 
mite; leg iv ending in many whiplike setae, one "seta" may bear 
pair of claws, being merely extremely modified portion of tarsus 

Scutacaridae 

3. Leg IV of female with ambulacra (claws and cup) 

Pyemotidae {— Pediculoididae) 

Leg IV of female without ambulacra, ending in terminal and sub- 
terminal whiplike setae Tarsonemidae 

Podapolipodidae Oudemans, 1931 

Figure 107 

Diagnosis: Parasites of insects. The females lack spherical pseudo- 
stigmatic organs and are without the complete number or with de- 
formed legs; the female may be legless in the adult stage. The che- 
licerae are needle-like, the palpi are rudimentary, and the legs have 
claws and caruncle. 

This family shows the greatest degeneration or specialization of all 
the mites, remaining more or less in the larval stage. The first stage is 
a sexually undifferentiated larva which has three pairs of legs, the 
posterior pair separate from the other two and almost on the end of 
the body; on the posterior of the body is a small tubercle bearing two 
adhering, long, whiplike setae which are lost in the adults. 



160 



Acarology 



In Locustacarus trachealis Ewing the sexually mature female retains 
the appearance of the larvae and the posterior setae, which are lost in 
the other members of the family. The TarsopoUpus are the least de- 
generate. The male has four pairs of normal legs but appears similar 
to the males of the other genera which have only three pairs of legs. 
The female has three pairs of legs, the third pair being on the pos- 
terior portion of the body. During the parasitic life the body becomes 
strongly swollen. Both the males and females of Eutarsopolipus are 

similar to the larvae in having 
three pairs of legs. In the female 
during the parasitic stage the hys- 
terosoma stretches so that the 
third pair of legs moves posteriorly 
to give the mite a flasklike shape. 
In the Tetrapolipiis the male has 
three pairs of legs but the female 
loses the third pair. Legs i and ii 
are quite short but maintain the 
normal segmentation. During par- 
asitism the body swells to about 
three times its length. The male of 
Podapolipus has the three pairs of 
legs but the female develops from 
the larva into a completely degen- 
erate form with only the first pair 
of legs present. These legs are ex- 
tremely short but are divided into three to five segments. In the position 
where legs ii would join the body are two diverticulae which flank the 
sides of the gnathosoma to give the anterior end of the body a charac- 
teristic appearance. The body may become rather swollen and the 
shape depends upon gravity and other external influences. 
Genera: 




Figure 107 Locustacarus 
Ewing. Young female. 



trachealis 



3. 



Podapolipus Rovelli and Grassi, 1888 (= Pimelofia Tragardh, 

Type, Podapolipus reconditus Rovelli and Grassi, 1888 

Eutarsopolipus Berlese, 1913 

Type. Eutarsopolipus lagenaeformis Berlese, 1913 

Locustacarus Ewing, 1924 

Type. Locustacarus trachealis Ewing, 1924 

TarsopoUpus Berlese, 1911 

Type. TarsopoUpus corrugatus Berlese, 1911 



1902) 



Trombidiformes 161 

5. Tetrapolipus Berlese, 1911 

Type. Tetrapolipus batocerae Berlese, 1911 

Discussion: These mites are parasitic on other arthropods. Locus- 
tacarus trachealis Ewing is found in the tracheae of grasshoppers in 
the United States and South Africa. Tetrapolipus rhynchophori Ewing 
was taken from beneath the elytra of Rhynchophorus palmarum, a 
palm weevil from Panama. Podapolipus reconditus Rovelli and Grassi 
is to be found under the elytra of certain European beetles; Podapo- 
lipus grassi Berlese, P. bacillus Berlese, and P. diander Volkonsky are 
external parasites of grasshoppers. 

The most complete study of these mites has been made by Volkon- 
sky 1940 on Podapolipus diander, a parasite of Locusta migratoria L. 
in Algeria. Young females of the mites are usually found under the 
posterior extension of the pronotum in the first three instars of the 
grasshopper. In the fourth and fifth instars the mites attach and lay 
eggs on the body under the rudimentary elements of the elytra and 
wings. When the grasshopper molts, the immature mites that have 
hatched from the eggs and the females that have not yet engorged and 
oviposited leave the cast skin and attach to the host grasshopper again. 
The adult grasshoppers harbor these mites in the folds between the 
mesothorax and metathorax and on the parts of the thorax covered 
with the elytra, on the underside of the elytra near the base, and along 
the main veins of the wings, usually on the ventral side. The first-stage 
females of the mites transform into adults. These adults mature and 
produce parthenogenetically an egg from which a "small" male imme- 
diately hatches. This "small" male mates with the parent female, and 
the latter begins to lay eggs which hatch within five or six days to pro- 
duce females and "large" males. These males are parasitic on the fe- 
males, perforating the abdomen of the female mites and at times killing 
them. These first-stage females attach to the intersegmental membranes 
of the grasshopper, feeding by piercing the integument, and gradually 
migrate toward the posterior segments and congregate at the genitalia. 
Mites are spread from one grasshopper to another when the grass- 
hoppers mate. If the temperature rises to about 80.6 F many of the 
mites leave the host at night and crawl into crevices in the soil or to 
the tips of grass blades, attempting to attach to any object with which 
they come into contact. If they attach to Locusta migratoria the life 
cycle is continued; otherwise they die. The mites may develop con- 
tinuously during the summer and pass the winter as eggs or as first- 
stage females attached to the grasshoppers. 



162 Acarology 

Lociistacanis trachealis Ewing lives in the principal tracheae and 
air sacs of grasshoppers, all stages being found in this habitat. The 
mites probably obtain nourishment by piercing the walls of the tra- 
cheae and air sacs and sucking the blood of the host. The body of the 
female, when gravid, extends to several times its former size. The eggs 
are laid in the tracheae; the female sometimes contains six to eight 
fully developed eggs and many more in different stages of development. 

Rejerences: 

Ewing, H. E. 1924. New tarsonemid mites (Order Acarina, family Tar- 
sonemidae). Proc. Ent. Soc. Wash. 26(3) : 66-69. 

Rovelli, G., and B. Grassi. 1888. Di un singolare acaride, Podcipolipiis 
reconditus, nobis. Bol. Soc. Ent. Ital. 20:59-63, PI. XV. 

Volkonsky, M. 1940. Podcipolipiis diander, n. sp., acarien heterostygmate 
parasite du criquet migrateur {Locusta migrator ia L.) Archiv. Inst. 
Pasteur Algerie 18(3) :321-340. 

Wehrle, L. P., and P. S. Welch. 1925. The occurrence of mites in the tra- 
cheal system of certain orthoptera. Ann. Ent. Soc. Amer. 28(1) :35- 
44. 

Scutacaridae Oudemans, 1916 

Figure 108 

Diagnosis: The dorsal plates of the female 
are divided into tergites, the anterior plate cov- 
ering the gnathosoma like a roof. These mites 
are usually round and flat. Female leg iv is 
elongated and may or may not have claws 
which end in strong setae. 



Figure 108 Sciitacarus inediocritarsus Vitzthum. 
Venter of female. (After Vitzthum 1925) 



Genera: 

1. Scutcicarus Gros, 1845 (= Disparipes Michael, 1884) 

Type. Acariis acarorum Goeze, 1780 {— Scutcicarus femoris Gros, 
1845 = Disparipes bombi Michael, 1884) 

2. Acarapis Hirst, 1921 

Type. Tarsonemus woodi Rennie, 1921 




Trombidiformes 163 

3. /)/v^m/?^5 Berlese, 1 903 

a. Diversipes s. str. 

Type. Disparipes exhamiilatus Michael, 1886 

b. Microdispus VdioXi, 1911 

Type. Microdispiis obovatus Paoli, 1911 

4. Imparipes Berlese, 1903 

a. Imparipes s. str. 

Type. Imparipes hystricinus Berlese, 1903 

b. Heterodispus FsLoVi, 1911 

Type. Imparipes elongatus Tragardh, 1904 

5. Microdispodides Vitzthum, 1914 

Type. Pediculoides amaniensis Oudemans, 1912 

(= Microdispodides wichmanni Vitzthum, 1914) 

6. Pygmodispus Paoli, 1911 

a. Pygmodispus s. str. 

Type. Pygmodispus equestris Paoli, 1911 

b. A Hod is pus VaoVi, 1911 

Type. Pygmodispus (Allodispus) latisternus Faoli, 1911 

7. Variatipes FsLoYi, \9\l 

Type. Disparipes nudus Berlese, 1886 

Discussion: These mites are minute, bizarre creatures, found in moss, 
soil, and sod samples throughout the world, and on various insects 
such as Formica and Lasius. One member of this family is a pest of 
honey bees. Acarapis woodi (Rennie) is the cause of the "Isle of 
Wight Disease" which is to be found in Europe. This scutacarid in- 
fests the tracheal tubes of bees and causes the eventual death of the 
host. The life cycle takes place within the tracheal tubes, although 
adult mites are to be found crawling through the hair of infested bees 
whereby they can be transferred from bee to bee. The mite causes 
injury to the bee by: (1) the parasite living upon the host fluids caus- 
ing active injury; (2) possibly a toxic secretion; (3) mechanical stop- 
page of the tracheae which prevents air from reaching the individual 
organs or cutting off the air supply to-the nerve centers which control 
the bee's activities. This mechanical disturbance is probably the most 
important. Since the bees can neither fly nor feed this becomes a nu- 
trition problem. 

References: 

Hirst, S. 1922. Mites injurious to domestic animals. Brit. Mus. (Nat. Hist.) 
Econ. Ser., No. 13. 



164 



Acarology 



Jacot, A. P. 1936. Two unrecorded species of Scutacaridae from the 
Southern Appalachians. Canad. Ent. 68:225-229, Figs. 1-3. 

Paoli, Guido. 1911, Monografia del "Tarsonemidi." Redia 7:215-281, Pis. 
VII-XI. 

Rennie, J., et al. 1921. Isle of Wight Disease in hive bees. Trans. Roy. Soc. 
Edinburgh 52(4), No. 29:737-779. 



Pyemotidae Oudemans, 1937 

(= Pedicuioididae Berlese, 1907) 
Figures 109-112 

Diagnosis: The anterior dorsal shield does not project anteriorly like 
a roof. Leg iv of the female is similar to legs ii and iii. The females 
have a capitate organ between coxae i and ii except in Acarophenax. 
The chelicerae are stylet-like and the palpi are small and simple. 





Figure 109 Py emotes (= Pedicii- 
loides) ventricosus (Newport). Dor- 
sum of female. 



Figure 110 Py emotes (= Pedicu- 
loides) ventricosus (Newport). Dor- 
sum of male. 



Genera: 
1. 



Py emotes Amerling, 1862 (= Heteropus Newport, 1850, nam. prae- 

occ. — Pediculoides Targioni-Tozzetti, 1878) 
Type. Py emotes eccoptogasteri pruni Amerling, 1862 
Acarophenax Newstead and Duvall, 1918 
Type. Acarophenax triholii Newstead and Duvall, 1918 
Pavania Lombardini, 1949 
Type. Pavania fusiformis Lombardini, 1949 



Trom b id i form es 



165 



4. Phthiroides Oudemans, 1937 

Type. Phthiroides megnini Oudemans, 1937 

5. Pygmephorus Kramer, 1877 

Type. Pygmephorus spinosus Kramer, 1877 

6. Resinacarus Vitzthum, 1927 

Type. Resinacarus resinatus Vitzthum, 1927 

7. Siteroptes AmQvWng, 1861 (= Therismoptes AmcrXing, 1861 = Pedi- 

culopsis Reuter, 1907) 
Type. Acarus graminisugus Hardy, 1851 

8. Tarsonemoides Tragardh, 1904 

Type. Tarsonemoides termitophilus Tragardh, 1904 





Figure 111 Py emotes (=i Pediculoides) 
ventricosus (Newport). Partially grav- 
id female. 



Figure 112 Siteroptes (= Pediculop- 
sis) graminum (Reuter). Respiratory 
system of gravid female. 



Discussion: The life cycle of Pyemotes (= Pediculoides) ventricosus 
(Newport) is as follows. Males and females are produced viviparously 
and are sexually mature at birth. The female is fertilized immediately 
after emergence and seeks a suitable host and pierces it with the stylet- 
like chelicerae. As it feeds the tip of the abdomen becomes enormously 
distended and the eggs develop and hatch within the swollen bag. The 
developing mites complete all their stages within the parent and do not 
emerge until mature. The first to emerge are the males, usually only 
a small number. These males feed very little and pierce the parent 



166 Acarology 

"sphere" in order to obtain food. They do not leave the mother but 
remain clustered about the genital opening and fertilize the females as 
they emerge. A full-sized gravid female is capable of producing 200 
to 300 offspring, and retains its vitality throughout the birth of its 
progeny. 

The life cycle of Siteroptes {— Pediculopsis) gramumm (Reuter) 
is even more interesting than that of the preceding species. During at- 
tachment to food the hysterosoma of the female swells from 100 to 500 
times the original body volume and within this sack the eggs are formed 
and develop into adult mites. In this species, however, there is a mass 
birth marked by a breakdown of the hysterosoma, although an early 
larva, nymph, or especially male may be extruded before the mass birth. 
Only a few males are born, each brood containing at least one male. 
Mating takes place within the sack before birth, as well as after birth. 
Virgin females give rise to males, which have the haploid number of 
chromosomes. This species, as well as Pyemotes, possesses heteromor- 
phic males. 

Other members of this family are little known and apparently of no 
economic importance. Banks 1915 stated that migratorial forms of a 
Pygmephonis have been found on a mole, flies, and thrips, and Vitz- 
thum states that Pygmephorus is carnivorous. Pygmephonis americanus 
Banks has been reported as a "pseudoparasite" of Musca domestica and 
Stomoxys calcitrans. Jacot 1936 has described a few east coast species 
and given a key to distinguish the more common genera Pyemotes 
{— Pediculoides) , Siteroptes (= Pediculopsis), Pygmephorus, and 
Resinacarus. 

Pyemotes {— Pediculoides) ventricosus (Newport) is the causative 
agent of the hay or grain itch. Normally it is an ectoparasite of various 
insect larvae such as the Angoumois grain moth, Sitotroga cerecdella 
(Olivier), the satin moth, Stilpnotia salicis (L.), the peach twig borer, 
Anarsia lineatella Zeller, and of many other insects. When grain in- 
fested with the parasitized grain moth larvae is handled at threshing, 
in storage, or on the docks, these mites will attack man, especially in 
hot weather when the need for moisture is great, and cause an intense 
itching. All parts of the body are affected, although the arms and neck 
are the regions usually attacked. As many as a thousand bites have 
been recorded from one individual. They cannot burrow under the 
skin or persist long on man, however. Swan 1934 describes the erup- 
tions as follows: 'The wheals vary in size and form with different 
subjects. They present, especially after rubbing, a raised whitish area 



Trombidiformes 167 

with a small central vesicle, which marks the seat of the puncture. The 
blanched area is surrounded by a rosy red areole. The lesions may 
itch severely, especially when warm in bed, or when the body is heated 
by exertion. Rubbing and scratching usually break the central vesicle 
and the possibility of secondary infection then arises. Itching usually 
subsides in two to three days, but the marks may last longer." Web- 
ster 1910 states that some severe cases show general systemic symp- 
toms such as a "rise of temperature from 99° to 102°; in one case the 
temperature rose to 103.8°; the pulse rate is accelerated to 100, or as 
high as 110 — in one case to 130. Other symptoms were intense head- 
ache, anorexia, nausea, in some cases vomiting, and a mild form of 
diarrhoea. In severe cases some complained of general joint pains and 
backache; in these the urine was examined and albumin in small 
amount was found, but no casts or blood. When the acute symptoms 
disappeared so did the albumin." Asthma due to these mites has also 
been reported. Generally, the mite is not considered important in con- 
trolling insect pests, although in isolated cases or in the laboratory, 
colonies of larvae may be completely eradicated by this mite. The dis- 
tribution of this species appears to be world-wide. Until recently only 
one species, Pyemotes {— Pediculoides) ventricosus, was recognized 
but Oudemans 1937 has described several more. 

Siteroptes {— Pediculopsis) graminum (Renter) superficially re- 
sembles the preceding species, but is a pest of grasses and grains, 
causing considerable damage to wheat, oats, barley, and rye, as well 
as being the active agent in the dissemination of the spores of the car- 
nation bud rot, Sporotrichum poae, in the United States. Infested ce- 
reals may be malformed and stunted, and often silvered, leading to 
the common name of "silver top." 

References: 

Cooper, K. W. 1937. Reproductive behaviour and haploid parthenogenesis 

in the grass mite, Pediculopsis graminum (Reut.) (Acarina, Tarso- 

nemidae). Proc. Natl. Acad. Sci. 23(2):41-44. 
. 1940. Relations of Pediculopsis graminum and Fusarium poae to 

central bud rot of carnation. Phytopathology 30(10) :853-859. 
Herfs, A. 1926. Okologische Untersuchungen an Pediculoides ventricosus 

(Newp.). Berl. Zoologica, Heft 74, Stuttgart. 
Jacot, A. P. 1936. An undescribed mite from the southern Appalachians. 

Canad. Ent. 68(4):82-85. 
Oudemans, A. C. 1937. Tijdschr. v. Ent. 80, Verslag IV-VIII. 



168 



Acarology 



Swan, D. C. 1934. The hay itch mite, Pediciiloides ventricosiis (Newp.) 
(Acarina, Pediculoididae) in South Australia. J. Agr. South Austral. 
37:1289-1299. 

Webster, F. M. 1910. A predaceous and supposedly beneficial mite, Pe- 
diciiloides, becomes obnoxious to man. Ann. Ent. Soc. Amer. 3(1): 
15-39, Pis. III-V. 

Tarsonemidae Kramer, 1877 

Figures 113-115 

Diagnosis: The tarsonemids have a segmented body and an anterior 
dorsal shield which lacks a rooflike projection. Leg iv of female differs 
from legs ii and iii in that it ends in an apical and subapical whiplike 




Figure 113 Tarsonemus setifer Ewing. 
Dorsum of male. 



Figure 114 Tarsonemus setifer Ewing. 
Dorsum of female. 



setae. Tarsonemella and Tarsonemus typhae Oudemans 1929 lack the 
clavate organ between coxae i and ii while others have such an organ. 
The chelicerae are stylet-like and the palpi simple. Heteromorphic 
males are present in this family. The group of genera now included 
under the tarsonemids is heterogeneous and probably needs further 
revision. 



Trombidiformes 169 

Genera: 

1. Tarsonemus Canestrini and Fanzago, 1876 

Type. Chironemus miniisculiis Canestrini and Fanzago, 1876 

2. Avrosia Oudemans, 1928 

Type. Acariis translucens Nietner, 1861 

3. Hemitarsonemus Ewing, 1939 

Type. Tarsonemus tepidariorum Warburton, 1904 

4. Pseiidotarsonemoides Vitzthum, 1921 

Type. Pseudotarsonemoides eccoptogasteris Vitzthum, 1921 

5. Tarsonemella Hirst, 1923 

Type. Tarsonemella africana Hirst, 1923 

Discussion: The tarsonemids illustrate a highly simplified type of 
life cycle. There are only four stages: egg, larva, quiescent nymphal 
stage in which the larva transforms into a mature adult (there being 
no active nymph) , and the adult. The males are heter- 
omorphic and the fourth pair of legs is used for clasp- 
ing the female during copulation. This pair of legs is 
extremely important in the identification of the species. 
The females lay one egg at a time, the hysterosoma 
being adapted with a series of overlapping segments to 
allow for the expansion of the body. The mites appear 
to prefer humid, sheltered conditions and disappear 
in many cases after the onset of high temperatures. '§^"^^ 

„ . , . Tarsonemus 

This is a widely distributed group of mites, being phyllopherus 
found throughout the warmer parts of the world. Al- Ewing. Leg iv 
though some of the species appear to be scavengers p -^^^Vq/^^ 
and predators, many are of economic importance 
because they cause serious injury to plants. The following species 
which have proved to be injurious to their hosts indicate the wide 
range of host plants and the importance of this family. 

Tarsonemus pallidus Banks is a serious pest of cyclamens in the 
United States and of strawberries in Europe; T. waitei Banks injures 
the peach tree in various parts of the United States; T. spirijex Marchal 
damages oats in Europe and has been reported from Arizona and 
Kansas in the United States; T. laticeps Halbert, the bulb scale mite, 
is a pest of narcissus bulbs in Europe and the United States, causing 
reduction in the number of flowers produced; T. ananas Tryon is an 
agent in the transmission of a pineapple rot in Australia. Hemitarso- 
nemus latus (Banks) is listed as being a pest of a wide assortment of 
plants throughout the world, such as tea in Ceylon, Cinchona sp. in 




170 Acarology 

Sumatra, Hevea sp. in the Netherlands Indies, tomato, cyclamen, del- 
phinium in the United States, and cotton in the Belgian Congo. 

Tarsonemiis sp. have also been recorded as being taken from lungs 
of persons suffering from asthma and other respiratory ailments. 

References: 

Carter, H., G. Wedd, and V. St. E. D'Abrera. 1944. The occurrence of 

mites (Acarina) in human sputum and their possible significance. 

India Med. Gaz. 79(4) : 163-168. 
Ewing, H. E. 1939. A revision of the mites of the subfamily Tarsoneminae 

of North America, the West Indies, and the Hawaiian Islands. U.S. 

Dept. Agr. Tech. Bull. 653. 
Hambleton, E. J. 1938. A ocorrencia do acaro tropical "Tarsonemus latus 

Banks," (Acar. Tarsonemidae). Causador da rasgadura das folhas 

nos algodoais de S. Paulo. Arch. Inst. Biol. [Sao Paulo] 9(19) : 201- 

209, Pis. 19-23. 
Moznette, G. F. 1917. The cyclamen mite. J. Agr. Res. 10(8) :373-390. 
Soysa, E., and M. Jayawardena. 1945. Pulmonary acariasis: a possible 

cause of asthma. Brit. Med. J. No. 4383, pp. 1-6. 
Vrydagh, J. M. 1942. Etude de I'acariose du cotonnier, causee par Hemi- 

tarsonemus latus (Banks) au Congo Beige. Pubs. Inst. Natl, pour 

I'Etude Agron. Congo Beige, Ser. Sci., No. 28. 

PROSTIGMATA KRAMER, 1877 

These mites have a respiratory system with the stigma opening at 
or near the base of the chelicerae. 

Key to the Prostigtnata 

1. Body normal; shape neither wormlike nor annulate 2 

Body small, wormlike, annulate; with eight legs; parasites in skin 
pores Demodicidae 

2. Living on land 3 
Living in water Hydrachnellae ^ 

3. Without thumb-claw process on palpus 4 

With thumb-claw process on palpus composed of spine or claw 
on palpal tibia and ventrally placed palpal tarsus 21 

4. Gnathosoma extended into very long, conelike process 5 
Gnathosoma short, not conelike 7 

1 The "water mites" are included as a complete unit with keys to simplify presentation. 



Trombidiformes 171 

5. Gnathosoma free, not enclosed in sheath 6 

Gnathosoma enclosed in sheath formed by extension of body wall; 
body hard; no suture between propodosoma and hysterosoma; 
chelicerae elongated with small, equal, distal shears; with two 
pairs of genital suckers Cryptognathidae 

6. Palpi long, turned inward; distal segment clawlike, adapted for 
grasping; body with external plates; with two pairs of genital 
suckers Cunaxidae 

Palpi long, elbowed, sensory organ; distal segment of palpus with 
usually two long, sensory setae; chelicerae elongated with small, 
equal, distal shears; body soft without surface plates; with three 
pairs of genital suckers Bdellidae 

7. Movable chela sharp, small, for piercing; not opposed to fixed 
chela 8 

Movable chela usually with teeth; opposed to fixed chela and 
adapted for biting and grasping 12 

Movable chela long, whiplike, for piercing; with stylophore; 
small mites; allied to the Tetranychidae but without thumb-claw 
process Phytoptipalpidae 

8. With two pairs of genital suckers 9 
Without genital suckers 10 

9. With a pair of long, fine, sensory setae on both propodosoma and 
hysterosoma; without peritremes Ereynetidae 

With sensory setae only on propodosoma; with peritremes; with 
small, clawlike pulvillus Paratydeidae 

10. Without peritremes, legs I normal; free-living 11 

With peritremes; chelicerae needle-like, extrusible, for piercing; 
palpi minute, difficult to see; legs i highly specialized for grasping 
hairs in many cases (rather heterogeneous group of genera re- 
lated to Cheyletidae but lacking strongly developed palpi; thumb- 
claw complex present but difficult to see because of reduction in 
size) Myobiidae 

11. Legs with netlike armor; movable chela minute, almost invisible; 
found in nasal passage of birds Speleognathidae 

Legs without netlike armor; movable chela large, visible; free- 
living Tydeidae 



172 Acarology 

12. Without well-developed pseudostigmata or pseudostigmatic organs 

on propodosoma 13 

With well-developed pseudostigmatic and pseudostigmatic organs 
on propodosoma (Endeostigmata of Grandjean 1939) 16 

13. With "Rhagidia organ" on tarsus i; coxae i-ii and lu-iv in two 
separate groups 14 

Without "Rhagidia organ" on tarsus i; coxae platelike, contigu- 
ous; armored with lenslike eyes and usually with large, lenslike 
organs behind eyes; with two pairs of genital suckers; palpal end 
segment small, pointed, with long end setae Labidostommidae 

14. With small, distorted cheliceral shears, not for grasping 15 

With large, cheliceral shears, for grasping; body soft, with two 
pairs of genital suckers; palpal end segment large, rounded, with 
many short setae Rhagidiidae 

15. Soft-bodied, without projection over rostrum; with two pairs of 
genital suckers Eupodidae 

Hard-armored, with projection or shield over rostrum; with two 
pairs of genital suckers Penthalodidae 

16. With three pairs of genital suckers; eyes present or absent 17 
With two pairs of genital suckers; eyes present or absent 18 

17. With single pair of sensory setae on propodosoma Terpnacaridae 
With two pairs of sensory setae on propodosoma Pachygnathidae 

18. With two pairs of sensory setae on propodosoma 19 

With single pair of sensory setae on propodosoma; tarsi mono- 
dactyle; no eyes Alicorhagiidae 

19. Tarsi with two or three claws 20 

Tarsi monodactyle; body clearly segmented; legs iv adapted for • 
jumping; eyes probably present in all genera Nanorchestidae 

20. Legs i-iv tridactyle; no eyes; anterior pair of sensory setae in 
special depression; fixed chela almost lacking Lordalychidae 

Leg I bidactyle; legs ii-iv tridactyle; two pairs of eyes; no special 
depression for sensory setae; fixed chela normal Sphaerolichidae 

21. Movable chela developed into a straight, stylet-like, extrusible 
piercing organ 22 

Movable chela strong, hinged non-extrusible piercing organ 26 



Trom b idi formes 1 73 

22. Movable chela straight, stiff, of varying lengths, no stylophore 
(mandibular plate) 23 

Movable chela long, whiplike, curving within body; basal che- 
liceral segments fused and form stylophores (mandibular plates); 
without crista and with lenslike eyes; no genital suckers (Phytopti- 
palpidae related to this family but do not possess thumb-claw 
process on palpus) Tetranychidae 

23. Chelicerae long, slender, capable of being withdrawn deeply into 
the body; dorsal sensory areas and sensory setae present 24 
Chelicerae short and not capable of being extended to such ex- 
tent; with M-like prominent peritreme on gnathosoma; no dorsal 
sensory areas; with large pincer-like palpi for grasping Cheyletidae 

24. Without genital suckers; with sensillary area and/or crista 25 
With genital suckers; no sensillary areas; palpi small, entire mouth 
parts capable of being withdrawn into body cavity Calyptostomidae 

25. Mouth parts small, capable of being withdrawn into the body; 
propodosoma usually drawn out into long nose Smaridiidae 
Mouth parts large, not capable of being withdrawn into body; 
propodosoma not drawn out into long nose or snout Erythraeidae 

26. Without strong body armor; with normal leg setae 27 

With several strongly sclerotized dorsal plates; legs i and ii, espe- 
cially I, with several large spines on tubercles giving rake effect 

Caeculidae 

27. Palpal thumb not large; inconspicuous, at times hard to see 28 
Palpal thumb large and conspicuous 29 

28. With three pairs of genital suckers; dorsal sensory setae in some 
cases set in characteristic pits or pseudostigmata; tarsal claws 
large, serrate Teneriffiidae 
Without genital suckers; no specialized sensory setae on dorsum; 
tarsal claws not serrate; usually modified to live beneath scales of 
lizards; no suture between propodosoma and hysterosoma 

Pterygosomidae 
Without genital suckers; two pairs of sensory setae on propodo- 
soma; with tarsal suckers or claws; free-living; body divided by 
suture Pseudocheylidae 

29. Palpal tarsus ventral 30 
Palpal tarsus distal; large red mite, with radiating legs; free peri- 
tremes Anystidae 



174 Acarology 

30, Large mites with sensory areas on propodosoma 32 
Small mites; no dorsal sensory areas 31 

31, With three pairs of genital suckers; without eyes; tarsi with claws 
but without pulvillus; tarsus i with seven rodlike sensory setae 

Pomerantziidae 

Without genital suckers; with one or two pairs of eyes; tarsi with 
claws and pulvillus; tarsus i with only one rodlike sensory seta 

Raphignathidae 

32, Adults not figure-8-shaped and with numerous setae on tectum 
if present; larvae usually with more than one dorsal plate; setae 

on pedipalpal coxa usually anterior to palpal femur Trombidiidae 

Adults usually figure-8-shaped, with only one or two setae on 
tectum; larvae with a single dorsal plate (with exception of one 
genus with a pygidial plate); seta on pedipalpal coxa posterior to 
palpal femur Trombiculidae 

Eupodidae Koch, 1842 

(= Penthaleidae Oudemans, 1931) 
Figure 116 

Diagnosis: The eupodids are yellowish or greenish, and occasionally 
flecked in color. Their legs are usually reddish or black flecked with 
red (Penthaleus, Halotydeus). They are small- to medium-sized mites 
from 0.160 to 1 mm. long. Fast moving and extremely fragile the 




Figure 116 Penthaleus major (Duges). Lateral view of female showing dorsal 
anus. Somewhat flattened by mounting. Upper left, chelicera. 



Trom b idiform es 1 75 

eupodids are more or less pear-shaped with the narrow end to the rear. 
Either a strong or weak suture separates the propodosoma from the 
hysterosoma. Their skin is soft, finely striated, and weakly haired. An 
eye spot appears on each side of propodosoma and a pair of pseudo- 
stigmata with weakly differentiated sensory setae is present. Leg i of 
Linopodes is up to four times as long as the body while leg iv of Eu- 
podes is somewhat thicker than the other legs and often has a very 
thick femora. The tarsi have two claws and a haired empodium. The 
palpi have four movable segments and the chelicerae are shearlike 
but have small, somewhat deformed, or modified chelae. Two pairs of 
genital suckers are present. In Penthaleiis the anus is dorsal, while in 
Halotydeus it is terminal, and in other genera ventral. 

Genera: 

1. Eiipodes Koch, 1836 

Type. Eupodes hiemalis Koch, 1838 

2. Cocceupodes Thor, 1934 

Type. Eupodes clavifrons R. Canestrini, 1886 

3. Hcdotydeus^CY\Q^Q, \^9\ 

Type. Notophallus hydrodromus Berlese and Trouessart, 1889 

4. Linopodes Koch, 1836 

Type. Acarus motatorius Linnaeus, 1758 

5. Penthcdeus Koch, 1836 (= Notophallus R. Canestrini, 1886) 
Type. Tetranychus major Duges, 1834 (= Penthaleus haemotopus 

Koch, 1836) 

6. Protacarus Hirst, 1923 (fossil) 
Type. Protacarus crani Hirst, 1923 

7. Protereunetes Berlese, 1923 

Type. Micrereunetes {Protereunetes) agilis Berlese, 1923 

The Eupodidae has been split into three families by European work- 
ers — Penthaleidae Oudemans, 1931, Penthalodidae Thor, 1933, and 
Eupodidae. The characters used to separate the Penthalodidae from 
the others appear to be substantial but those used for the family Pen- 
thaleidae do not give a clearly defined group. Because of this the Pen- 
thaleidae {Penthaleus and Halotydeus) are placed back into the Eu- 
podidae. 

Discussion: The life cycle of these mites is simple — egg, larva, 
nymph, adult. Halotydeus destructor (Tucker) has been studied in 
Australia. The dry season is bridged over by a resting egg laid in Oc- 
tober. They are laid in great numbers on the soil surface, under clods 



176 Acarology 

or sticks, and are highly resistant to heat, drought, or desiccating 
winds. Moisture and sunshine are necessary for the hatching of these 
over-summering eggs. The aduU is a soft-bodied mite whose front legs 
act as sensory organs. The leaf surfaces are broken by the rasping 
mouth parts and the sap is sucked up. The adult lives from twenty-five 
to fifty days and is killed off by heat and drought. The mite prefers 
light, well-drained soils. 

Very few species are known. Of these Linopodes antennaepes Banks 
(?possibly L. motatorius L. ) is a pest of mushrooms. This long-legged 
mite damages the mushrooms by chewing off the feeder roots of the 
growing plant, causing the stems to constrict at the base and injuring 
or killing the developing mushroom. The mites are found on or near 
the surface of the mushroom beds, and under boards and leaves out 
of doors. The eggs are laid in groups in the soil; they hatch in a short 
time into larvae which are similar to the adults except for the number 
of legs, genitalia, and other small differences; nymphs possess eight 
legs and are similar to the adult forms. The mite is found in the United 
States and in Europe. 

Eupodes species are remarkable jumpers and the fourth pair of legs 
are enlarged for this purpose. They are usually to be found in moss 
and under leaves. 

Penthaleus major (Duges) has been reported attacking peas, clover, 
oats, wild mustard, and lupine in California, barley in Arizona, and 
wheat in Oklahoma and Texas. It is a pest of pasture and forage crops 
in Australia and South Africa, as well as of lettuce and peas in France. 

Halotydeus destructor (Tucker) is a serious pest of vegetable and 
leguminous crops in Australia and South Africa. 

References: 

Baker, E. W. 1946. New species of North and Central American mites of 
the family Penthaleidae (Acarina). J. Wash. Acad. Sci. 36(12) :421- 
425. 

Solomon, M. E. 1937. Experiments on the effects of temperature and hu- 
midity on the survival of Halotydeus destructor (Tucker), Acarina 
fam. Penthaleidae. Austral. J. Expt. Biol, and Med. Sci. 15:1-16. 

. 1937. Behaviour of the red-legged earthmite, Halotydeus destructor, 

in relation to environmental conditions. J. Anim. Ecol. 6(2) : 340-361. 

Thor, Sig. 1934. Einzelne neue, besonders Norwegische Eupodes Arten 
mit einigen alteren Arten verglichen. Zool. Anz. 105:201-215. 

Womersley, H. 1941. The red-legged earth-mite (Acarina, Penthaleidae) 
of Australia. Trans. Roy. Soc. South Australia 65(2) : 292-294. 



Trombidiformes 



177 



Penthalodidae Thor, 1933 

Figure 117 

Diagnosis: The body of these mites is black, usually with red flecks, 
and the leg segments are red. They are small to medium-sized mites 
from 0.330 to 1.5 mm. long and pear-shaped with the narrow end to 
the rear. The propodosoma and 
hysterosoma are not separated or 
at best are separated only by a 
shallow suture. The integument is 
strongly sclerotized, reticulate, or 
punctate. An eye is situated on each 
side of the propodosoma (missing 
in Tectopenthalodes according to 
Tragardh). Setae on the legs and 
body are sparse and short; a pair 
of pseudostigmata with sensory 
setae is present. The legs are long 
and narrow, usually with six mov- 
able segments. All tarsi have haired 
empodia between the claws. The 
palpi are narrow with four mova- 
ble segments and the chelae are 

small, shearlike, and somewhat distorted. There is a tectum-like pro- 
jection over the rostrum. These mites possess two pairs of genital 
suckers. 




Figure 117 Penthalodes turneri Baker. 
Dorsum of female. 



Genera: 

1. Penthalodes Murray, 1877 (= Penthaleus Berlese, 1891 = Chromo- 

tydeus Berlese, 1903) 
Type. Megamerus ovalis Duges, 1834 

2. Stereotydeus Berlese, 1901 

Type. Stereotydeus notophcdloides Leonardi, 1901 

3. Tectopenthalodes TY'i.gkYdh., 1907 

Type. Penthaleus villosus Trouessart, 1903 

Discussion: These mites are to be found in moss, debris, and such. 
They appear to be predaceous, but nothing is actually known of their 
biology or importance. The immature forms are similar to the adults 
but lack the heavy sclerotization. Several North American species have 



178 



Acarology 



been described by Baker 1946, who at that time placed them in the 
family Penthaleidae which in this paper is considered to be a part of 
the Eupodidae. 

Rejerences: 

Baker, E. W. 1946. New species of North and Central American mites of 

the family Penthaleidae (Acarina). J. Wash. Acad. Sci. 36(12) :421- 

425. 
Womersley, H. 1935. On some Australian and South African species of 

Acarina of the genus Stereotydeus (Penthalodidae). Proc. Linn. Soc. 

New South Wales 60(1-2) :79-82. 



Bdellidae Duges, 1834 

Figure 118 

Diagnosis: In general the bdellids are of reddish color, but owing to 
gut contents the mites may appear greenish, brown, or flecked with vio- 
let (seldom black as in Trachymolgus) . They are medium-sized to large 

mites measuring from 0.450 to 3.50 
mm. long (excluding the gnatho- 
soma). Elongated and pear-shaped 
these mites possess a sharp rostrum 
which gives them the name of 
"Snout Mites." A suture is situated 
between the propodosoma and hys- 
terosoma. In general the integument 
is thin and striated {Trachymolgus 
is armoured and possesses round 
tubercles); often a subcutaneous 
shield is to be found on the pro- 
podosoma. Four pseudostigmata 
with sensory setae are present and 
two pairs of separated eyes are lo- 
cated on the lateral margins of the 
propodosoma {Cyta and Mono- 
trichobdella have an unpaired, an- 
terior, median eye). The legs have six movable segments and all tarsi 
are provided with short pretarsus, two claws, and pulvillus. The palpi 
have five movable segments, the genu and tibia being very short, the 
femur very long, the tarsus either cylindrical and long or short and 




Figure 118 Bdella willisi Baker and 
Balock. Dorsum of female with left 
half showing striae. 



Trombidiformes 1 79 

keglike with two end setae, except for Monotrichobdella which pos- 
sesses one. Normally the genu and tibia are bent, giving the palpi 
an elbowed appearance. Chelicerae are elongated (more compact in 
Cyta) with one or more dorsal setae and very small, usually weak 
shears. Three pairs of genital suckers are present. Grandjean 1938 has 
divided the BdelUdae into four subfamilies. 

Key to the Bdellidae 

1. With well-developed genital tracheae; venter of rostrum with only 
two pairs of strong setae and two pairs of weak anterior setae 2 

Without well-developed genital tracheae; venter of rostrum with 
six pairs of strong setae and two pairs of weak anterior setae 3 

2. With unpaired seta anterior to genital opening Cytinae 
With pair of setae anterior to genital opening Spinibdellinae 

3. Trichoboth (long sensory seta) on tibiae i, n, and rv and tarsi 

m and iv Odontoscirinae 

Trichoboth on tibiae i and iv and tarsi ni and rv Bdellinae 

Cytinae Grandjean, 1938 
Genera: 

1. Cytav. Hey den, 1826 

Type. Scirus latirostris Hermann, 1804 

2. Trachymolgus Berlese, 1923 

Type. Bdella nigerrima G. Canestrini and Fanzago, 1876 

Spinibdellinae Grandjean, 1938 
Genera: 

1. SpinibdellaThoT, 1930 

Type. Spinibdella reducta Thor, 1930 

2. Biscirus Thor, 1913 

Type. Bdella silvatica Kramer, 1881 

3. Monotrichobdella Baker and Balock, 1944 

Type. Monotrichobdella max-osburni Baker and Balock, 1944 

Bdellinae Grandjean, 1938 

Genus: 

Bdella Latreille, 1795 (= Scirus Hermann, 1804, non Thor, 1931) 
Type. Acarus longicornis Linnaeus, 1758 (= Scirus vulgaris Her- 
mann, 1804) 



J 80 Acarology 

Odontoscirinae Grandjean, 1938 

Genera: 

1 . Odontoscirus Thor, 1913 

Type: Bdella virgukita G. Canestrini and Fanzago, 1876 

2. Bdellodes Oudemans, 1937 {— Scirus Thor, 1931, non Hermann, 

1804) 
Type. Scinis longirostris Hermann, 1804 

3. Neomolgiis Oudemans, 1937 (= Molgiis Thor, 1931 nom. praeocc.) 
Type. Acanis littoralis Linnaeus, 1758 

4. Thoribdella Grandjean, 1938 

Type. Bisciriis meridiomdis Thor, 1931 

Vnassigned genera: The following genera were not adequately de- 
scribed and cannot be placed under any of the above subfamilies. 

1. C aenobdella OudQmdiX\s, \92>1 

Type. Bdella crassipes C. L. Koch, 1839 

2. Hoplomolgus Berlese, 1923 

Type. Bdella capillata Berlese, 1891 {non Kramer, 1881) 

(= Molgus {Hoplomolgus) tuherculatus Berlese, 1923) 

3. Hoploscinis Thor, 1937 

Type. Scirus dubitatus Womersley, 1933 

4. Troglobdella Oudemans, 1937 
Type. Scirus obisiuin Gervais, 1841 

Discussion: Males and females are usually very similar, the differ- 
ences lying in the genital organs, although occasionally there may be 
some slight differences in the palpi. The egg is slightly elliptical and is 
covered with a number of clavate spines or projections. They are laid 
on the soil, in leaf mold, or wherever the mite happens to be. They 
hatch into the six-legged larva, which is similar to the adult except in 
the number of legs and in lacking genital plates. The proto-, deuto-, 
and trito-nymphal stages have the genital plates, two pairs of genital 
suckers, fewer genital setae, and are smaller than the adult. 

This family appears to be distributed throughout the world in both 
extremes of climate. They are predaceous on other mites and small 
insects. Little is known of the effect of these predators on their prey 
except for one species, Biscirus lapidarius (Kramer) which controls 
the lucerne flea Sminthurus viridis L. in certain localities in Western 
Australia. These mites are usually to be found in moss, lichens, leaf 
mold, and debris, wherever there is an abundance of small insects and 
other mites. 



Trombidiformes J 81 

Paul DeBach reports in correspondence that a Bdella sp. occurring 
commonly on orange trees in Orange County, California, is preda- 
ceous on collembola. The mite, after capturing its prey by squirting 
onto it a liquid "silk" and enmeshing its appendages, would suck the 
body contents. When this mite was eliminated by a DDT application 
the collembola population increased tremendously. 

The common North American species is Bdella oblonga Say, which 
is to be found along the east coast, west to Texas and as far south as 
Panama. It is one of the largest of the Bdellidae, measuring up to about 
1300 /x in length and can be distinguished by its reticulate inverted 
U-shaped propodosomal shield. Biscirus lapidarius (Kramer), which 
is known from Europe and Australia, has also been taken in Mexico. 
Bdella virgata Ewing is to be found in the United States and Mexico. 

References: 

Baker, E. W., and J. Balock. 1944. Mites of the family Bdellidae. Proc. 

Ent. Soc. Wash. 46(7) : 176-184. 
Currie, G. A. 1934. The Bdellid mite Biscirus lapidarius Kramer, preda- 
tory on the lucerne flea Sminthurus viridis L. in Western Australia. 

J. Austral. Council Sci. & Indus. Res. 7(1) :9-20. 
Grandjean, F. 1938. Observations sur les Bdelles (Acariens). Ann. Soc. 

Ent. France 107:1-24. 
Thor, Sig. 1931. Bdellidae, Nicoletiellidae, Cryptognathidae. Das Tierreich 

56, pp. 1-65. 
Womersley, H. 1933. A preliminary account of the Bdellidae (Snout 

Mites) of Australia. Trans. Roy. Soc. South Austral. 57:97-107. 
. 1933. A possible biological control of the clover springtail or lucerne 

flea {Sminthurus viridis L.) in Western Australia. J. Austral. Council 

Sci. & Indus. Res. 6(2) :83-91. 

Rhagidiidae Oudemans, 1922 

Figures 119-122 

Diagnosis: The rhagidiids are whitish, yellow, or rosy-colored mites. 
Light-sensitive and fast-moving, they range from small to medium size 
(0.350 to 1.80 mm.). They are long, delicate, and without armor. A 
suture separates the propodosoma and hysterosoma. The setae are 
simple and long. A pair of poorly developed pseudostigmata with only 
slightly modified sensory setae is located on the propodosoma. Usually 
eye spots are present. The legs of these mites are relatively long and 
narrow and have five movable segments. The femora of legs i and ii are 



182 



Acarology 



divided ventrally and the femora of leg in and iv are divided com- 
pletely into two parts. All tarsi have two claws and a haired empodium. 
Four movable segments comprise the palpi which have no thumb or 
claw. The palpal tarsus is cylindrical and about as thick as the tibia. 





Figure 119 Rhagidia gelida Thorell. 
Dorsum of female. (After Oudemans 
1928) 



Figure 120 Rhagidia gelida Thorell. 
Chelicera and trachea. (After Oude- 
mans 1926) 




Figure 121 Rhagidia gelida Thorell. 
Venter of female. (After Oudemans 
1928) 



Figure 122 Tarsus i of Rhagidia sp. 
showing profile of Rhagidia organ. 



Trombidiformes 183 

The chelicerae are strong with opposed, grasping chelae. The rhagidiids 
have two pairs of genital suckers. 

Genera: 

1. Rhagidia Thorell, 1871 (= Scyphius C. L. Koch, 1836 nom. prae- 

occ; — Noerneria Canestrini, 1886) 
Type. Rhagidia gelida Thorell, 1871 

2. Coccorhagidia Thor, 1934 

Type. Noerneria clavifrons R. Canestrini, 1886 

Discussion: Very little information is to be found on these mites. 
They are known from Europe and North America, but future collect- 
ing will probably reveal them to be world-wide in distribution. They 
appear to be predaceous and, since they are rather common in certain 
localities, they may play a more important role in the general relation- 
ship of small insects and mites than has been thought. They live in 
soil, humus, and moss. Rhagidia pallida Banks is from New York, 
New Hampshire, and Washington, D.C., and is to be found on the 
ground under damp boards or stones; R. cavicola Banks is from Mam- 
moth Caverns, Kentucky; Banks says this species is somewhat common 
and is often found under stones on which egg masses of the cave spi- 
der, Anthrobia mammouthia Telkpf. occur. 

Nothing is known of the life cycle of these mites, other than that all 
stages are somewhat similar in appearance except for the larval forms, 
which possess only six legs. 

Cryptognathidae Oudemans, 1902 

Figure 123 

Diagnosis: The cryptognathids are small, scarlet-red mites measuring 
from 0.300 to 0.400 mm. in length. The body is oval and lacks a su- 
ture between the propodosoma and the hysterosoma. The dorsum has 
a net-like skin pattern and the skin is punctate. A pair of lenslike eyes 
is located on each side of propodosoma. The chitinous extensions of 
the body form a tube which is not closed ventrally and through which 
the gnathosoma is capable of being extruded or withdrawn into the 
body. The chelicerae are shearlike while the chelae are small, almost 
straight, untoothed, and sharp for piercing. No genital suckers are 
present. 



184 
Genus: 



Acarology 



Cryptognathus Kramer, 1878 

Type: Cryptognathus lagena Kramer, 1878 




Figure 123 Cryptognathus cucurbitae 
Berlese. Dorsum of female. 



Discussion: These mites live in 
moss and under stones. Sig Thor 
1931 lists only two species and one 
variety. Cryptognathus lagena Kra- 
mer is known from Germany, Hol- 
land, Switzerland, Italy, France, 
England, Ireland, and Norway and 
is to be found under stones and in 
moss. C. cucurbita Berlese was 
taken in Italy and specimens have 
been found in Sciurus n. niger nest 
in Florida. C. cucurbita var. sub- 
nitida Berlese was described from 
Somaliland, Africa. Nothing is 
known of their habits other than 
that they appear to be predaceous. 



Reference: 

Thor, Sig. 1931. Bdellidae, Nicoletiellidae, Cryptognathidae. Das Tierreich 

56:78-81. 



Labidostommidae Oudemans, 1904 

Figures 124-126 

Diagnosis: These mites are free-living, completely armored, yellow- 
ish predators measuring from 0.57 to 1.5 mm. in length and are egg- 
shaped. Their propodosoma is divided into two sections, the posterior 
portion shading into the hysterosoma but without a clear line of de- 
marcation. There are two pairs of pseudostigmatic organs, one on each 
of the propodosomal plates. One lenslike eye is located on each side of 
propodosoma and at times an unpaired eye is placed in the middle 
of the propodosoma on the anterior margin. A large lenslike organ 
on lateral margins behind eyes may be present. The palpus has four 
segments and the chelicerae have large, strong, opposed chelae. The 



Trom b idijorm es 



185 



legs have six movable segments and the coxal plates are contiguous. 
All tarsi are provided with two claws and tarsi ii, iii and iv with a 
clawlike empodium. Two pairs of genital suckers are present. In the 





Figure 124 Labidostomma luteum Figure 125 Labidostomma neotropica 

Kramer. Lateral view of chelicera. Stoll. Dorsum of female 

(After Thor 1931) 

female the genital and anal openings are united in a circular plate 
while the male genital opening is separate although in the same posi- 
tion. 




Figure 126 Labidostomma neotropica (Stoll). Venter of female. 
Genera: 

1. Labidostomma Kramer, 1879 [= Panoplia v. Heyden, 1826 {nom. 
praeocc.) = Nicoletiella R. Canestrini, 1882 — Ceratoacarus 
Ewing, 1913] 
Type. Labidostomma luteum Kramer, 1879 (Some believe this to be 
a synonym of Acarus denticulatus Schrank.) 



186 Acarology 

2. Eunicolana Berlese, 1911 

Type. Eunicolana tuhercukita Berlese, 1911 

Discussion: Grandjean 1942 has studied the family in some detail 
and the following life history is based on his studies. The adults feed 
readily on Collembola and small, immature, oribatid mites. Eggs are 
laid separately and without protection. The adult is able to carry the 
egg from one place to another by seizing it between the first pair of 
legs and resting it on the extremity of the chelicerae. The egg, which 
is rather large, hatches in about twelve days into the larva. The larva 
does not feed and is mobile for only a few hours. It seeks a place to 
transform into the protonymphs. The proto-, deuto-, and tritonymphs 
greatly resemble the adult mites in structure and food habits. 

The Labidostommidae is a small family of little known mites found 
in Europe, South Africa, North and Central America, and Brazil in 
South America. The mites live in moss, humus, and soil and are pre- 
daceous on other mites and small insects. Many species are character- 
ized by a lateral protuberance behind the lateral eyes, the function of 
which is unknown. The family is represented in the United States by 
Labidostomma pacifica (Ewing) and from the southern United States 
to Panama by L. neotropica (Stoll). 

References: 

Grandjean, F. 1942. Observations sur les Labidostommidae. Bull. Paris 
Mus. Nat. d'Hist. Nat. Ser. 2, 14(2) :118-125; (3):185-192; (5): 
319-326; (6):414-418. 

Thor, Sig. 1931. Bdellidae, Nicoletiellida, Cryptognathidae. Das Tierreich 
56:66-77. 

Ereynetidae Oudemans, 1931 

Figure 127 

Diagnosis: The ereynetids are reddish yellow or colorless white. They 
are small mites measuring from 0.220 to 0.500 mm. in length. The 
body has a suture located between the propodosoma and the hystero- 
soma. Their integument is soft and striated. Ereynetes has a compli- 
cated shield pattern on the propodosoma while Opsereynetes has a 
simpler pattern. Setae on the body are few but a pair of long sensory 
setae is situated on the propodosoma and another pair is located on the 
hysterosoma. Opsereynetes has eye spots but Ereynetes has a pair of 
lenslike eyes. The palpi are simple, lack either a thumb or a claw, and 



Trombidiformes 



187 



are three- to five-segmented. The digitus mobihs of chelicerae is sharp, 
for piercing, and extends beyond the digitus fixus. All tarsi have claws 
and haired pulvillus. Two pairs of genital suckers are present. 



Genera: 

1. Ereynetes Berlese, 1883 (= Micrereunetes Berlese, 1923) 
Type. Ereynetes berlesei Oudemans, 1928 

2. Opsereynetes ThoT, 1932 
Type. Opsereynetes norvegicus Thor, 1932 

3. Riccardoella Berlese, 1923 
Type. Acarus limacum Schrank, 1781 

Discussion: These mites are 
known from Europe, North Amer- 
ica, Java, Sumatra, and Japan and 
are likely to be found wherever 
careful collecting is made. They are 
moss-lichen and sometimes leaf in- 
habitants and appear to be preda- 
ceous. The species, Riccardoella 
limacum (Schrank) is to be found 
in Europe and North America on 
the common snail. Helix pomata L. 
This mite is at times abundant on 
the slimy parts of the snail but ap- 
parently does not cause its host any 
harm. Turk and Phillips 1946 have 
studied the slug mite and have 
worked out the life history as fol- 
lows. Eggs are laid in the mucus of 
the mantle cavity of the snail. The 
egg hatches into a six-legged larva 
which lacks the posterior pair of ab- 
dominal sensory setae and the geni- 
tal suckers. The proto- and deutonymphs resemble the adults. However, 
these workers state that this species exhibits neotony in that the deu- 
tonymphal stage (nympha generans) contains the eggs, whereas the 
adults examined were never found with well-developed ova. The fe- 
male deutonymph is either viviparous or ovoviviparous. The mites do 
not spend the entire time on the snail, but run along the ground and 




Figure 127 Opsereynetes rohustiis 
Baker. Dorsum of female. 



188 Acarology 

are able to find the host by following the slime trail. The food may be 
the slime or may be found off the snail. The mites and snails appear 
to live in perfect harmony with each other. 

References: 

Baker, E. W. 1945. Five mites of the family Ereynetidae from Mexico. 

J. Wash. Acad. Sci. 35(1):16-19. 
Grandjean, F. 1939. Observations sur les Acariens (5 serie). Bull. Paris 

Mus. d'Hist. Nat., Ser. 2, 11 (4) :394-401. 
Thor, Sig. 1933. Tydeidae, Ereynetidae. Das Tierreich 60:58-84. 
Turk, F. A. and Stella-Maris Phillips. 1946. A monograph of the slug mite 

— Riccardoella limacum (Schrank). Proc. Zool. Soc. London 115 

(3,4):448-472. 



Para tydeidae Baker, 1949 

Figure 128 

Diagnosis: These mites are prostigmatic and have peritremes as in 
the predaceous Cheyletidae. Their palpi are four-segmented, without 

the claw-thumb complex and with the 
tarsal segment terminal. The chelice- 
ral bases are fused, and the movable 
chela is short and nonretractile for 
piercing. The body is elongated and 
both the propodosoma and the hyste- 
rosoma are without plates. The skin is 
striated. The hysterosoma is divided 
dorsally by a distinct suture behind 
the third pair of legs. A few simple 
setae are located on the body and the 
propodosoma has two pairs of long 
sensory (?) setae, one pair of short 
setae, two pairs of lenslike eyes, and 
two pairs of lateral, peglike setae. The 
anal opening is situated on the venter 
at the rear. The genital opening, sep- 
arated from the anal opening, is lo- 
cated behind coxae iv, and has two 

pairs of genital suckers and from two 
Figure 128 Paratydeus alexanaeri • r • i ^ 

Baker. Dorsum of female. ^0 four pairs of genital setae. Coxae 




Trombidiformes 189 

i-ii and iii-iv are in two widely separated groups; coxae of the legs 
are fused with the body and the legs are sparsely haired. All tarsi 
have two claws and a small clawlike pulvillus; tarsus i has two 
short, rodlike, sensory setae. The paratydeids measure 0.366 mm. 
in length. 

Genus: 

1. Paratydeus Baker, 1949 

Type. Paratydeus alexanderi Baker, 1949 

2. Neotydeus Baker, 1950 

Type. Neotydeus ardisannae Baker, 1950 

3. Scolotydaeus Berlese, 1910 

Type. Scolotydaeus bacillus Berlese, 1910 

Discussion: These mites, which apparently are soil livers, appear to 
be predators. Only three species are known. 

References: 

Baker, E. W. 1949. Paratydeidae, a new family of mites (Acarina). Proc. 

Ent. Soc. Wash. 51 (3) : 119-122. 
. 1950. Further notes on the family Paratydeidae (Acarina) with 

a description of another new genus and species. J. Wash. Acad. 

Sci. 40(9):289-291. 

Speleognathidae Womersley, 1936 

Figure 129 

Diagnosis: The speleognathids are small, light yellowish-brown mites 
measuring about 0.80 mm. in length. The skin is soft and has no 
shields. A few short setae are present on the body while a pair of long 
sensory setae is to be found on the propodosoma. Short and simple 
palpi which lack the claw-thumb complex are present. The chelicerae 
are reduced and the movable chela is a tiny, sharp point. Lenslike eyes 
may or may not be situated on the propodosoma. There is no suture 
between the propodosoma and the hysterosoma. The legs are short, 
with netlike sclerotization and the coxae are divided into two groups. 
All tarsi have claws and a haired pulvillus. No genital suckers are 
present. 

Genus: 

Speleognathus Womersley, 1936 

Type. Speleognathus australis Womersley, 1936 



190 



Acarology 



Discussion: Speleognathus australis Womersley has been collected 
in moss and from around cattle watering tanks in Australia. Speleo- 
gnathus sturni Boyd is to be found in the nasal passages of starlings in 

the eastern United States. Boyd 
1948 found that the birds with 
these mites had more nasal secre- 
tion, or mucus, than those not 
parasitized. There is apparently a 
close relationship between this 
group and the Ereynetidae in 
structure and biology, for Riccar- 
doella limacum (Schrank) in- 
habits the snail, whereas S. sturni 
is in the warm mucus of the nasal 
passage of the starling. Boyd 
points out the possibility of a 
common ancestor of the two 
mites. This species may be rather 
generally distributed and will 
probably be found wherever the 
starling or related birds are es- 
tablished. 
The larval form of S. sturni Boyd, although basically similar to the 
adult, shows an interesting deviation in that tarsus i does not possess 
claws or pulvillus but tibia i has a long, bifurcate, clawlike process. 

References: 

Boyd, Elizabeth. 1948. A new mite from the respiratory tract of the star- 
ling (Acarina, Speleognathidae). Proc. Ent. Soc. Wash. 50(1):9-14. 

Womersley, H. 1936. On a new family of Acarina, with description of a 
new genus and species. Ann. Mag. and Nat. Hist. 18(104) :3 12-3 15. 




Figure 129 Speleognathus sturni Boyd. 
Venter of female. (From Boyd 1948) 



Tydeidae Kramer, 1877 

Figures 130, 131 

Diagnosis: The tydeids are weakly colored in yellow, brown, red, or 
green. They are very small mites measuring from 0.100 to 0.300 mm. 
in length (they are usually about 0.20 mm. long). They are of various 
shapes but usually an egg-shape predominates. The skin is soft with 
punctate striations, and in some species it has a punctate or reticulate 
pattern. There are few body setae and a pair of sensory setae is located 



Trombidijormes 



191 



on the propodosoma. The propodosoma and hysterosoma are usually 
separated by a distinct suture. The legs are five- or six-segmented and 
the tarsi have short pretarsus, two claws, and haired pulvillus (leg i 




Figure IW Tydeiis starri Baker. Lat- 
eral view of chelicera and dorsum of 
female. 



Figure 131 Tydeiis starri Baker. Ven- 
ter of female. 



of Pronematus lacks the claws and pulvillus, and in Proctotydaeus leg 
I is without claws and pulvillus whereas legs ii-iv lack the pulvillus). 
The chelicerae have a thick basal piece and a very sharp-pointed, fixed 
chela from which a dagger-like, almost straight, movable chela extends 
in such a way that the chelicerae are not truly chelate. Some species 
lack eye spots, while others have two and three eye spots. No genital 
suckers are present. 

Genera and subgenera: 

1. Tydeus Koch, 1836 (= Microtydeus Thor, 1931 = Brachytydeus 
Thor, 1931 = Melanotydeus Berlese, 1910 = Stylotydeus Thor, 
1933 = Lasiotydeus Berlese, 1908? = Calotydeiis Oudemans, 1937 
= Tectotydeus Oudemans, 1937) 
a. Tydeus s. str. 

Type. Tydeus kochi Oudemans, 1928 (= Tydeus croceus Koch, 
1836 inon Acarus croceus Linnaeus, 1758) 



192 Acarology 

b. Tydaeohis Berlese, 1910 

Type. Tydaeiis atomiis Berlese, 1908 

c. Triophtydeiis Thor, 1932 (= Tridilatydeus Baker, 1946) 
Type. Tydeiis triophthcdmus Oudemans, 1929 

2. CoccotydeusThoY, \9?>\ 

Type. Coccotydeus globifer Thor, 1931 

3. Lorryia Oudemans, 1925 (= Raphitydeus Thor, 1933) 
Type. Lorryia superba Oudemans, 1925 

4. Coleotydaeus Berlese, 1910 

Type. Coleotydaeus rhombicus Berlese, 1910 

5. Pronematus G. Canestrini, 1886 

a. Pronematus s. str. 

Type. Pronematus bonatii Canestrini, 1886 

b. Pronecupulatus BsikQT, 1944 

Type. Pronecupulatus anahuacensis Baker, 1944 

c. Proctotydaeus BQr\Q?,Q, 1911 

Type. Proctotydaeus viator Berlese, 1911 

6. Retetydeusl^hoT, \92>\ 

Type. Retetydeus catenulatus Thor, 1931 

The family has been divided in the past into too many genera based 
on such characters as size, width, length of setae, type of setae, and 
presence or absence of eye spots. It is believed that the above pres- 
entation is a more correct and simpler one. 

Discussion: These mites are world-wide in distribution and appear 
to be predaceous on small insects and mites and their eggs. There is 
an indication that certain species, however, may be plant feeders but 
more observation is necessary. One species, Tydeus molestus (Mo- 
niez), is a minor pest to man in an isolated region in Belgium. They 
cause irritation by the bite to human beings and to domestic animals. 
Tydeus calif ornicus (Banks) is predaceous on the citrus bud mite, Ace- 
ria sheldoni (Ewing), in Southern California. Pronematus ubiqiutus 
(McGregor), a mite found throughout California, is common on the 
fig trees where it preys on the fig mite, Aceria ficus (Cotte). Lorryia 
superba Oudemans, a European species, has been found in California, 
and L. mali (Oudemans), another European species, has been taken 
on apple leaves in Nova Scotia. 

Most species are to be found in moss, lichens, or on plant leaves in 
association with other mite colonies. The life cycle is a simple 
one; each female deposits eggs singly. This develops into the larva, 
nymph, and adult, all stages being quite similar, and the adult acquir- 
ing the genital opening. The male is similar to the female except in 



Trombidiformes 



193 



having a much smaller genital opening. In no case has any species 
appeared to be of great importance in controlling a pest, although they 
may be of minor value. 

Reference: 

Thor, Sig. 1933. Tydeidae, Ereynetidae. Das Tierreich 60:1-57. 



Cunaxidae Thor, 1902 

Figure 132 

Diagnosis: These are small, red 
mites from 0.350 to 0.500 mm. 
long (not including the gnathos- 
oma which is long and conelike). 
A suture separating the propo- 
dosoma from the hysterosoma is 
present. The integument is soft, 
finely striated, punctate in spots, 
and in many cases has extensive 
plates. There are four distinct 
sensory setae on propodosoma. 
Eyes may or may not be present. 
The legs have six movable seg- 
ments; all tarsi have claws and 
pulvillus. The palpi are used for 
grasping and are large, pincer- 
like, and usually have apophyses 
and strong spines on the inner 
side. The palpal end segment is 

clawlike, and the chelicerae are elongated with a very small, distal, 
sickle-like digitus mobilis. Two pairs of genital suckers are present. 

Genera and subgenera: 

1. Cunaxa v. Heyden, 1826 (= Scirus sensu Berlese = Dactyloscirus 

Berlese, 1916) 
Type. Scirus setirostris Hermann, 1804 

2. Bonzia Oudemans, 1927 

Type. Bonzia halacaroides Oudemans, 1927 

3. Coleoscirus Berlese, 1916 

Type. Coleoscirus halacaroides Berlese, 1916 




Figure 132 Cunaxa capreohis (Ber- 
lese). Dorsum of male. 



194 Acarology 

4. Ciinaxoides Baker & Hoffmann, 1948 (= Eiipalus Koch, 1838 nom. 

praeocc. — Haleupalus Radford, 1950) 
Type. Eiipalus croceiis Koch, 1838 

5. Rosenhofia Oudemans, 1922 

Type. Rosenhofia niachairodus Oudemans, 1922 

6. Scinila Berlese, 1887 

Type. Scinila inipressa Berlese, 1887 

Discussion: No species has been reported as of great economic im- 
portance, although they are predators on other mites and small insects. 
The family is widely distributed and many species are more or less 
cosmopolitan. Cimaxa capreolus (Berlese) is a European species to 
be found in Africa, the United States, and Mexico; C. setirostris (Her- 
mann) is another species which is distributed throughout the world, 
as is C. inennis (Tragardh) and C. taurus (Kramer). This latter spe- 
cies is rather distinctive in having immensely long palpi with long inner 
spines and apophyses and is fairly common in leaves or leaf mold in 
the northeastern United States. Cimaxoides parvus (Ewing) is from 
Iowa, where it was described as a "real enemy of the oyster shell 
scale," although it was not numerous. C. pectinatus (Ewing) is dis- 
tributed from the United States (Illinois) to Panama. 

Larvae and nymphs are similar to the adults. Males are similar to 
females except in having much smaller genital plates and perhaps other 
minor variations, as in Cimaxa capreolus (Berlese) in which the male 
has a much smaller apophysis on the third palpal segment than does 
the female. Nymphal forms appear to have three pairs of genital setae 
rather than four, as do the adults. A nymph of Cunaxoides pectinatus 
(Ewing) has the three pairs of genital setae, a small body and long 
legs, and no dorsal shield but the entire body is striated. Otherwise it 
is similar to the adult. The mites are usually to be found in moss, hu- 
mus, and on leaves. 

The family appears to be closely related to the Halacaridae, and it 
has been stated that Bonzia is a "landgoing" halacarid. 

References: 

Baker, E. W., and Anita Hoffmann. 1948. Acaros de la familia Cunaxidae. 

Anales de la Escuela Nacional de Ciencias Biologicas V(3-4):229- 

273. 
Ewing, H. E. 1917. New Acarina. Part II. Descriptions of new species and 

varieties from Iowa, Missouri, Illinois, Indiana, and Ohio. Bull. Amer. 

Mus. Nat. Hist. 37(2): 151. 



Trom b idiform es 



195 



Thor, Sig, and C. Willmann. 1941. Acarina. Prostigmata 6-11 (Eupo- 
didae, Penthalodidae, Penthaleidae, Rhagidiidae, Pachygnathidae, 
Cunaxidae). Das Tierreich 71 a, 

Lordalychidae Grandjean, 1939 

Figures 133-136 

Diagnosis: The lordalychids are medium-sized mites measuring from 
0.30 to 0.40 mm, long. They have a globular body which is constricted 
between the propodosoma and the hysterosoma. The propodosoma is 
rather small in relation to the hysterosoma. The skin is pebbled, ru- 





Figure 133 Lordalychiis peraltiis 
Grandjean. Lateral view of chelicera. 
(After Grandjean 1939) 



Figure 134 Lordalychiis peraltus 
Grandjean. Lateral view of female. 
(After Grandjean 1939) 



gose, and not smooth but with striae. Two pairs of propodosoma! 
sensory setae are present, the anterior pair being located in a special 
invaginated area. No eyes are present. The chelicerae are primitive 
with abortive, fixed chela. The palpus is simple and has no claw-thumb 
complex. The legs are situated at the anterior portion of the body; all 





Figure 135 Lordalychiis peraltus 
Grandjean. Dorsum of propodosoma. 
(After Grandjean 1939) 



Figure 136 Lordalychiis peraltus 
Grandjean. Venter of female. (After 
Grandjean 1939) 



196 



Acarology 



tarsi possess two claws and an empodium (the claws on Lordalycus 
have ventral rays; the pulvillus is rayed) . The femur is divided into basi- 
and telofemur. Two pairs of genital suckers are present. 

Genera: 

1. Lordalycus Gv2ind]Q2kn, \9?>9 

Type. Lordalycus peraltus Grandjean, 1939 

2. Hybalicus Berlese, 1913 

Type. Hybalicus fiabelUger Berlese, 1913 

Discussion: The discovery, with the aid of the phase microscope, of 
the prostigmatic type of tracheal systems opening at the base of the 
chelicerae in four families of the Endeostigmata of Grandjean indi- 
cates a definite relationship to the Prostigmata. The Endeostigmata 
form a closely knit group of families (Terpnacaridae, Pachygnathidae, 
Alicorhagididae, Nanorchestidae, Lordalychidae and Sphaerolichidae) 
and are at present retained within the Prostigmata. The families are 
little known and only a few species and genera have been described. 

Reference: 

Grandjean, F. 1939. Quelques genres d'acariens appartenant au groupe 
des Endeostigmata. Ann. des Sci. Nat., Zoo!., Ser. 11, 2: 1-122. 



Sphaerolichidae Grandjean, 1937 

Figures 137-139 




Figure 137 Sphaerolichus barbarus 
Grandjean. Dorsum of female. (After 
Grandjean 1939) 



Diagnosis: These mites have a 
whitish or yellowish color (in al- 
cohol). They are small to medi- 
um-sized (from 0.30 to 0.40 mm. 
long) . The body is globular, thick, 
and round while the skin is soft 
and striated or has punctiform 
striae. The propodosoma has a 




Figure 138 Sphaerolichus barbarus 
Grandjean. Lateral view of chelicera. 
(After Grandjean 1939) 



Trom b idiform es 



197 



tectum or anterior protuberance with an unpigmented ventral eye. 
There are also two pairs of lateral eyes. Two pairs of sensory setae 
are situated on the propodosoma. 
The body lacks a suture between 
the propodosoma and the hyste- 
rosoma. The legs are located an- 
teriorly in two closely approx- 
imated groups: femur i is divided 
into three sections; femora ii, in, 
and IV are divided into two sec- 
tions; tarsus I is bidactyle; tarsi ii, 
III, and IV are tridactyle (the 
claws and empodium are claw- 
like with short rays). The legs 
are adapted for jumping. The 
chelicerae have opposed chelae. 
The palpus has five segments and 

no claw-thumb complex. Two ^*g"»*^ ^^^ 
r •* 1 1 Grandjean. 

pairs of genital suckers are pres- Grandjean 
ent. 




Sphaerolichiis barbarus 
Venter of female. (After 
1939) 



Genus: 

Sphaerolichus Berlese, 1904 

Type. Sphaerolichus armipes Berlese, 1904 

Discussion: The sphaerolichids are little-known mites that live in a 
dry habitat in vegetable debris. A tracheal system opening at the base 
of the chelicerae was found in the only available species, an unde- 
scribed genus from California. Grandjean 1939 has also found tra- 
cheae in Sphaerolichus. 

Reference: 

Grandjean, F. 1939. Quelques genres d'acariens appartenant au groupe 
des Endeostigmata. Ann. des Sci. Nat., Zool., Ser. 11, 2:1-122. 



Nanorchestidae Grandjean, 1937 

Figures 140-141 

These colorless or reddish, with a brownish posterior, 

long). Their shape 



Diagnosis: 

mites are small in size (from 0.165 to 0.350 mm 



198 Acarology 

is more or less extended in length with a sacklike hysterosoma. 
The body is usually clearly (in Oehserchestes vaguely) segmented 
into gnathosoma, propodosoma, metapodosoma, and opisthosoma by 
sharply delineated constrictions. The skin is soft with fine striations 
and thirty-two specially formed setae are located on the dorsum. 
Palpi possess four or five segments, without thumb-claw complex. 
The chelicerae are chelate. Either no eyes are present {Oehser- 
chestes) or a small, simple, lenslike eye is located on each side of the 

propodosoma. Four sensory setae 
are on the propodosoma. There 
is no tectum. The legs are situated 
far anteriorly; legs iv are special- 
ized for jumping. The tarsi have 
only an empodial claw which can 
be withdrawn into a very deep 
claw-depression. Three pairs of 
genital suckers are present. 





Figure 140 Speleorchestes podiiroides 
Hirst. Dorsum of female. (After Hirst 
1917) 



Genera: 



Figure 141 Nanorchestes piilvinar 
Grandjean. First pair of propodosomal 
sensory setae showing arrangement of 
the long "activating" seta and the 
short, true sensory seta. (After Grand- 
jean 1942) 



1. Nanorchestes Topsent and Trouessart, 1890 (= Moimlichiis Berlese, 

1904) 
Type. Nanorchestes amphibius Topsent and Trouessart, 1890 

2. Speleorchestes Tv'?igkYd\\, 1909 {— Leptalicus Berlese, 1910). 
Type. Speleorchestes formicoriim Tragardh, 1909 

3. Oehserchestes Jacot, 1939 (= Coccorchestes Jacot, 1938 nom. prae- 

occ.) 
Type. Coccorchestes humicoliis Jacot, 1938 



Trombidiformes 199 

4. Caenonychus Oudemsins, 1903 

Type. Caenonychus fallcLx Oudemans, 1903 

Discussion: There are only a few described species, but the distri- 
bution is probably world-wide and these mites have been overlooked 
because of their minute size. They are usually to be found in moss and 
soil and it has been stated that Nanorchestes amphibius Topsent and 
Trouessart is practically marine in habit. They are probably preda- 
ceous. 

One species, Nanorchestes pulvinar Grandjean, presents an inter- 
esting arrangement in the forward pair of propodosomal sensory setae. 
The long "sense setae" activate a short seta which apparently is the 
true sensory organ. 

Grandjean 1942 lists the stages of Nanorchestes as larva, three 
nymphal, and adult. The males are differentiated from the females 
by the larger number and position of the genital setae. 

A Speleorchestes sp. from Mexico possesses a tracheal system open- 
ing at the base of the chelicerae. 

References: 

Grandjean, F. 1942. Observations sur les Acariens (7 Ser.). Bull. Paris 

Mus. d'Hist. Nat. Ser. 2, 14(4) :264-267. 
Womersley, H. 1944. Australian Acarina, families Alycidae and Nanorr 

chestidae. Trans. Roy. Soc. South Austral. 68(1) :133-143. 

Pachygnathidae Kramer, 1877 

Figures 142-144 

Diagnosis: These are small, whitish mites ranging from 0.30 to 0.40 
mm. in length. The skin is soft and may be striate, reticulate, or with 
diverse pattern. The pachygnathids possess an anterior protuberance 
or tectum which varies in shape. They have no median eye and may 
or may not have lateral eyes. The propodosoma is separated from the 
hysterosoma by a suture and has two pairs of sensory setae (in Pe- 
tralycus the anterior pair is globose while in Bimichaelia the posterior 
pair is globose). The hysterosoma may or may not be segmented. The 
chelae of the chelicerae are opposed and the palpus is five-segmented 
without the claw-thumb complex. The legs are in two distinct groups. 
All tarsi are provided with two claws and a pulvillus (the claws are 
simple and the pulvillus rayed); in Petralycus femora i, ii and iii are 



200 Acarology 

entire while iv is divided into basi- and telofemur. Three pairs of 
genital suckers are present. 





Figure 142 Petralycus unicornis 
Grandjean. Venter of female. (After 
Grandjean 1943) 



Figure 143 Petralycus unicornis 
Grandjean. Dorsum of female. (After 
Grandjean 1943) 



Genera: 
1 




Pachygnathus Duges, 1834 

Type. Pachygnathus villosus Duges, 1836 

Bimichaelia Thor, 1902 (= Michaelia Berlese, 1884 nom. praeocc.) 

Type. Michaelia augustana Berlese, 1884 

Petralycus Grandjean, 1943 

Type. Petralycus unicornis Grandjean, 1943 

Discussion: These mites are found in humus and 
vegetable debris and in the soil. They are prob- 
ably predators but very little is known of them. 
Bimichaelia diadema Grandjean has a larva, two 
tgure et)a- ^^^jyg nymphal stages, and an adult stage; Bimi- 

lycNS unicornis j f a •> o ' 

Grandjean. Lateral chaelia arhusculosa Grandjean and Petraycus uni- 
view of chelicera. cornis Grandjean have three nymphal stages. A 
1943T "^'^^ ^^'^" Bimichaelia sp. from southern United States was 

studied and found to have the tracheal system. 
References: 

Grandjean, F. 1942. Quelques genres d'acariens appartenant au groupe 
des Endeostigmata (2 Ser.) Premiere partie. Ann. des Scr Nat , Zool., 
Ser. 11, 4:85-135. 

. 1943. Quelques genres d'acariens appartenant au groupe des En- 
deostigmata (2 ser.) Deuxieme partie. Ann. des Sci. Nat., Zool., Ser. 
11, 5:1-59. 



Trombidiform es 



201 



Terpnacaridae Grandjean, 1939 

Figures 145-147 

Diagnosis: Granular and reddish in 
color the terpnacarids are small mites 
about 0.35 mm. in length. They are 
soft-bodied and have a somewhat sack- 
like, segmented hysterosoma. A suture 
is situated between the propodosoma 
and the hysterosoma. One pair of prop- 
odosomal sensory setae, one pair of 
lateral, lenslike eyes, an unpaired, an- 
terior median eye on the venter of the 
tectum or anterior protuberance of the 
propodosoma are present. The palpus 
is composed of five segments and does 
not have a claw-thumb complex. The 
chelicerae have opposed chelae. Di- 
vided into two groups, the legs are five- 
segmented and fairly long, especially 
legs I and iv; the femur is divided into 
two parts in legs i, in, and iv. All tarsi are provided with two claws 
and a pulvillus. Three pairs of genital suckers are present. 




Figure 145 Terpnacariis hoiivi- 
eri Grandjean. Dorsum of 
female. (After Grandjean 1939) 





Figure 146 Terpnacarus bouvieri 
Grandjean. Genital-anal region. (After 
Grandjean 1939) 



Figure 147 

Grandjean. 
1939) 



Terpnacarus bouvieri 
Palpus. (After Grandjean 



Genera: 

1 Terpnacarus Grandjean, 1939 

Type. Terpnacarus bouvieri Grandjean, 

2. Alycosmesis Grandjean, 1939 

Type. Sebaia palmata Oudemans, 1904 



1939 



202 Acarology 

3. Sebaia Oudemans, 1903 (= Monalichus Berlese, 
Type. Sebaia rosacea Oudemans, 1903 



1904) 



Discussion: These small mites are to be found in more or less dry 
situations in vegetable debris. Terpnacariis and Sebaia are both jump- 
ers but Alycosmesis is not. An apparently undescribed genus from 
Guatemala shows the prostigmatic tracheal system. 

Rejerence: 

Grandjean, F. 1939. Quelques genres d'acariens appartenant au groupe 
des Endeostigmata. Ann. des Sci. Nat., Zool., Ser. 11, 2:1-122. 



Alicorhagiidae Grandjean, 1939 

Figures 148-150 

Diagnosis: These mites are small (about 0.22 to 0.30 mm. long) 
and whitish in color with a brownish posterior. The body is not very 
elongated and a light suture is located between the propodosoma and 




Figure 148 Alicorhagia fragilis Berlese. Lateral view of chelicera (right) with 
detail (left). (After Grandjean 1939) 

the hysterosoma. The skin is soft with tuberculate striae. One pair of 
propodosomal sensory setae is present and the large frontal protuber- 
ance of the propodosoma bears two setae. There are no eyes. The 





Figure 149 Alicorhagia fragilis Ber- 
lese. Dorsum of female. (After Grand- 
jean 1939) 



Figure 150 Alicorliagia fragilis Ber- 
lese. Venter of female. (After Grand- 
jean 1939) 



Trombidiformes 



203 



chelicerae are opposed and there is no claw-thumb complex on the 
palpus. The legs are five-segmented and the femur is divided into 
basi- and telofemur; trochanters i and ii are also divided. All tarsi have 
a single retractable claw (pulvillus). Two pairs of genital suckers are 
present. 

Genus: 

Alicorhagia Berlese, 1910 (= Willania Oudemans, 1931 — Episto- 

malyciis Thor, 1931) 
Type. Alicorhagia fragilis Berlese, 1910 

Discussion: Grandjean 1939 reports Alicorhagia fragilis Berlese as 
being common in forest humus in France. 

Reference: 

Grandjean, F. 1939. Quelques genres d'acariens appartenant au groupe 
des Endeostigmata. Ann. des Sci. Nat., Zool,, Ser. 11, 2:1—122. 



Raphignathidae Kramer, 1877 

(= Stigmaeidae Oudemans, 1931; Caligonellidae Grandjean, 
Figures 151-154 

Diagnosis: The raphignathids 
are small, red mites, round in 
shape, with no suture or no dis- 
tinct suture between the propo- 
dosoma and the hysterosoma. 
They may or may not have vari- 
ous numbers of shields. 



1944) 




Figure 151 Homocaligiis sp. Palpus 
showing thumb and claw. (After 
Grandjean 1946) 



Figure 152 Mediolata niali (Ewing). 
Dorsum of female. 



204 



Acarology 



The integument is finely striated between the dorsal shields. One or 
two pairs of lenslike eyes may be present. The propodosomal sensory 
setae are undifferentiated. These mites have peritremes which at times 
enter into the basal portion of the chelicerae. The moderately long 
cylindrical palpal tarsus is located ventrally on the palpal tibia be- 
neath a small to large tibial claw; the movable chela is stylet-like for 
piercing. All tarsi have two claws and a rayed pulvillus; tarsi i and ii 
each have a single sensory organ. The coxae are either contiguous or 
separated into two groups. There are no genital suckers and the anal 
opening is either posterior or posterior dorsal. 





Figure 153 Raphignathiis sp. Dorsal 
view of gnathosoma. 



Figure 154 Raphignathiis cardinalis 
(Ewing). Dorsum of female. 



The discovery of two genera with the peritremes in the cheliceral 
bases but with large palpal claws and terminal anus has led to com- 
bining these three families, since they now grade into one another 
and since there are no clear-cut, so-called family characters. 



Genera: 

1 



Raphignathiis Duges, 1834 (= Syncaligus Berlese, 

Type. Raphignathiis ruberrimus Duges, 1834 

Acheles Oudemans, 1903 

Type. Acheles mirahilis Oudemans, 1903 

Apostigmaeiis Grandjean, 1944 

Type. Apostigmaeiis navicella Grandjean, 1944 

Barbiitia Oudemans, 1927 

Type. Stigmaeus anguineus Berlese, 1910 



1910) 



Trombidiformes 205 

5. Caligonella Berlese, 1910 

Type. Stigmaeiis humilis Koch, 1838 

6. Caligonus Koch, 1836 

Type, Caligonus piger Koch, 1838 

7. Eupalopsellus Sellnick, 1949 

Type. Eupalopsellus olandicus Sellnick, 1949 

8. Eupalopsis C2inQsXnm, \S^6 

Type. Eupalus maseriensis Canestrini and Fanzago, 1876 

9. Eustigmaeus ^qv\qsq, 1910 {— Liostigmaeus Thor, 1930) 
Type. Stigmaeus kermesinus Koch, 1841 

10. Homocaligus Berlese, 1910 

Type. Stigmaeus scapularis Koch, 1838 

11. Eedermulleria Oudtmsins, 1923 
Type. Caligonus segnis Koch, 1836 

12. Macrostigmaeus Berlese, 1910 

Type. Stigmaeus {Macrostigmaeus) serpentinus Berlese, 1910 

13. Mediolata R. Canestrini, 1890 {- Zetsellia Oudemans, 1927) 
Type. Stigmaeus longirostris Berlese, 1887 

14. N^o/?/2y//oZ)/w5 Berlese, 1886 

Type. Neophyllobius elegans Berlese, 1886 

15. Podaia Oudemans, 1923 

Type. Acarus rubens Schrank, 1781 

16. Stigmaeus Koch, 1836 (= Stigmaeodes Canestrini, 1890) 
Type. Stigmaeus cruentus Koch, 1836 

17. Storchia Oudemans, 1923 

Type. Caligonus robustus Berlese, 1885 

18. K///^/-5/fl Oudemans, 1927 

Type. Villersia vietsi Oudemans, 1927 

Discussion: Although distributed throughout the world only a few 
species are yet known. They are to be found in moss, lichens, 
straw, and leaves. At Santa Paula, California, Mediolata terminalus 
(Quayle) was seen preying on the citrus bud mite, Aceria sheldoni 
(Ewing) on lemon. The chelicerae were inserted into the bud mites 
and the body contents sucked out. Owing to the small numbers, its 
relative slowness, and the usual inaccessibility of the minute eriophy- 
ids beneath bud scales and fruit buttons, this predator is of no great 
value. No details of their biology are known other than that the eggs 
are red and laid singly beneath the fruit buttons. Eupalopsis pinicola 
Oudemans, a European species, has been collected in eastern Canada 
on apples and is probably predaceous on the other apple mites; it is 
predaceous on scale insects in Europe. Mediolata nova-scotiae Nesbitt 



206 



Acarology 



has been collected on apples in Nova Scotia. N eophyllobiiis sp. has 
been observed preying on crawler stages of scales in southern Cali- 
fornia. 

References: 

Grandjean, F. 1944. Observations sur les Acarines de la famille des Stig- 

maeidae. Archives des Sciences physiques et natureiies. Periode 5, 

26:103-131. 
. 1946. Au sujet de I'organe de Claparede. Archives des Sciences 

physiques et natureiies. Periode 5, 28:82-87. 
McGregor, E. A. 1950. Mites of the genus N eophyllobiiis. Bull. South. 

Calif. Acad. Sci. 49(2) :55-70. 
Vitzthum, H. 1929. Acari. Die Tierwelt Mitteleuropas 3(3) : 50-52. 




Figure 155 Pomerantzia 
charlesi Baker. Genital 
region of female. 



Pomerantziidae Baker, 1949 

Figures 155-157 

Diagnosis: These mites have a palpal 
thumb-claw complex and movable short 
chelae which are stylet-like. The peritreme 
is short and does not reach to the inner 
base of the chelicerae. There are several 
dorsal shields but no eyes and no differ- 
entiated sensory setae on the propodo- 
soma. The anus is terminal and there are 
three pairs of genital suckers. Seven rod- 
like and one conelike sensory setae appear 
on tarsus i and two rodlike sensory setae 
appear on tarsus ii. All tarsi have claws 
but no pulvilli. 



Genus: 



Pomerantzia Baker, 1949 

Type. Pomerantzia charlesi Baker, 



1949 



Discussion: This is a small (0.34 mm. long), raphignathid-like mite, 
which is to be found in peach orchard soil in Georgia, United States. 
The morphology and habitat indicate a predaceous life. 



Trombidiformes 



207 



Reference: 

Baker, E. W. 1949. Pomerantziidae, a new family of mites. J. Wash. Acad. 
Sci. 30(8):269-271. 





Figure 156 Pomerantzia charlesi 
Baker. Dorsal view of female. 



Figure 157 Pomerantzia charlesi 
Baker. Tarsus i showing sensory setae. 



Pterygosomidae Oudemans, 1910 

Figures 158, 159 

Diagnosis: These mites are parasitic on lizards, with the exception 
of Pimeliaphilus podapolipophagus Tragardh which is a parasite of 
cockroaches, and P. isometri Cunliffe, found on a scorpion. They are 
red and small to medium in size (from 0.160 to 1.30 mm. long). Those 
found on lizards are flat, baglike in oudine, and about twice as wide as 
they are long. The body setae range from few to many and are usually 
rodlike, leaflike, or fanlike. A shield, -either whole or divided, may or 
may not be present on the propodosoma. Also the pterygosomids may 
or may not possess a pair of lenshke eyes. The gnathosoma is terminal 
or deeply inserted into the body and the chelicerae are narrow, with 
a distorted, movable chela in the lizard parasites and a sharp, piercing, 
movable chela in the cockroach parasites. At the base of the gnatho- 
soma are prominent peritremes. The palpus has a thumb-claw complex 
but the thumb is not prominent. The coxae are located anteriorly in 
the lizard parasites while they are more normal in those parasitizing 



208 



Acarology 



the cockroach. The tarsi have a pair of claws, each with a pair of 

tenent hairs. No genital suckers 
are present and the anal opening 
is posterior. 




Figure 138 Pimeliaphiliis podapolip- 
ophagus Tragardh. Dorsum of female. 

Genera: 



Figure 159 Pterygosoina neiiinanni 
Berlese. A typical lizard parasite form. 
(After Hirst 1925) 



1. Pterygosoma Peters, 1849 

Type. Pterygosoma agamae Peters, 1849 

2. Geckobia Megnin, 1878 

Type. Geckobia latasti Megnin, 1878 

3. Geckobiellan\YSi,\9\l 

Type. Geckobia texana Banks, 1915 

4. Hirstiella Berlese, 1920 

Type. Geckobiella {Hirstiella) trombidiformes Berlese, 1920 

5. Ixodiderma Lawrence, 1935 

Type. Ixodiderma inverta Lawrence, 1935 

6. Pimeliaphilus Tragardh, 1904 ( = Pimeliaphiloides Vitzthum, 1942) 
Type. Pimeliaphilus podapolipophagiis Tragardh, 1904 

7. Scaphothrix Lawrence, 1935 

Type. Scaphothrix convexa Lawrence, 1935 

8. Zomirobia Lawrence, 1935 

Type. Zonurobia cordylensis Lawrence, 1935 

Discussion: The Pterygosomidae, for the most part, are parasites of 
lizards, usually being found beneath the scales of their host. Accord- 
ing to Hirst 1925: "When more than one form of Geckobia is found 



Trombidiformes 209 

on the same host, one form usually lives beneath the ventral scales and 
is flattened, being considerably wider than long and having scales in- 
stead of hairs on the venter. The second form occurring on the same 
host is usually to be discovered between the claw and pad of the toes, 
between the laminae of the pad, or between the toes themselves: this 
form is normally practically spherical in shape and has hairs instead 
of scales on the venter." Lawrence 1935 states: "Generally speaking, 
therefore, mite parasites are absent (i) in families of lizards in which 
scales are entirely absent or which lack imbricating scales, (ii) in gen- 
era where degeneration of the limbs has taken place, whether these 
degenerate forms are burrowing as in the Scincidae, or surface living 
as in the Zonuridae and Gerrhosauridae, and (iii) in certain isolated 
species of genera in which the majority of forms are parasitized." 

Very little is known about the biology of most of these species. The 
life cycle of all Pterygosomidae consists of larva, nymphochrysalis, 
nymph, teleiochrysalis, and adult in the female mites, but only the 
larva, chrysalis, and adult stages in the male mites. Lawrence 1935 
figures the larval, nymphal, and adult stages of Zonurobia cordylensis 
Lawrence. The immature forms are very similar to the adult; larva 
and nymph each possess a small eye plate or shield containing one 
seta; the adult does not have such a plate but does have the two eyes. 
In Pimeliaphilus podapolipophagus Tragardh, a parasite of cock- 
roaches, all stages are very similar and differences are small. Although 
this species has been placed in other families by various workers, it 
is truly related to the lizard parasites, being the more primitive, free- 
living type. P. isometri Cunliffe is a parasite of scorpions in the Philip- 
pine Islands. 

In the United States Pimeliaphilus podapolipophagus Tragardh has 
proved to be a pest in cockroach-rearing cages, at times causing enough 
damage to hamper rearing. Geckobiella texana (Banks) was described 
from Sceloporus fioridanus in Texas. Hirstiella trombidiformes Berlese 
is known from San Luis Potosi, Mexico, although its host is unknown. 

References: 

Hirst, S. 1925. On the parasitic mites of the suborder Prostigmata (Trom- 
bidioidea) found on lizards. J. Linn. Soc. London, Zool. 36:173-200. 

Lawrence, R. F. 1935. The prostigmatic mites of South African lizards. 
Parasitol. 27(1): 1-45. 

Lawrence, R. F. 1936. The prostigmatic mites of South African lizards. 
Parasitol. 28(1): 1-39. 



210 



Acarology 



Caeculidae Berlese, 1893 

Figures 160, 161 

Diagnosis: The caeculids are brownish black, moderately large mites 
from 1.0 to 2.60 mm. long. They are plump, short, broad, and some- 
what trapeziform in shape. There is no suture between the propodo- 
soma and the hysterosoma. The body is heavily armored, usually with 





Figure 160 Caeciilus calechius Mu- 
laik. Palpus. (After Mulaik 1945) 



Figure 161 Caeciilus pettiti Nevin. 
Dorsum of female. (After Nevin 1943) 



seven dorsal shields (three unpaired and two paired) surrounded by 
weakly striated or wrinkled skin. There are two pairs of lenslike eyes 
on each side of the propodosoma. An outstanding character is the row 
of tubercles on the inner side of leg i which supports very long, strong 
spines giving them the name of "rake-legged mites"; a similar row is 
on leg II. All tarsi lack pretarsi but have two ambulacral claws which 
are often of different sizes. There is no empodium. The short palpi 
have strong tibial claws and there is a ventrally placed tarsus or thumb 
on the tibia. The chelicerae are short and thick with a strong, sickle- 
like, movable chela and only a remnant of the fixed chela. No genital 
suckers are present. 

Genera: 

1. Ccieculus Dufour, 1832 

Type. Caeciilus echinipes Dufour, 1832 

2. Procaeculus Jacot, 1936 

Type. Procaeculus bryani Jacot, 1936 



Trom b id i form es 211 

Discussion: Andre 1935 states that the Caeculus are predators, slug- 
gish and slow, to be found in the sun or bare earth and rocks in dry 
places. In cold periods they take refuge in the moss. When disturbed 
they play possum. The eight-legged nymphs are similar to the adults 
but less chitinized; the six-legged larvae are also similar to the other 
stages. 

Most of the American species have been described by Mulaik 1945, 
from the southwestern United States. 



References: 

Andre, M. 1935. Notes sur le genre Caeculus Dufour (Acariens) avec 

descriptions d'especes nouvelles africaines. Bull. Soc. d'Hist. Nat. de 

FAfrique du Nord 26:79-127. 
Jacot, A. P. 1936. Some rake-legged mites of the family Cheyletidae. J. 

N. Y. Ent. Soc. 44:17-31. 
Lawrence, R. F. 1939. New South African species of the genus Caeculus 

(Acari). J. Linn. Soc. London, Zool. 40(273) :537-545. 
Mulaik, S. 1945. New mites in the family Caeculidae. Bull. Univ. Utah 

35(17) :l-23. 
Nevin, F. R. 1943. Caeculus pettiti, a new species of mite from Virginia. 

Ann. Ent. Soc. Amer. 36(3) :389-393. 



Tetranychidae Donnadieu, 1875 

Figures 162-164 

Diagnosis: These mites are plant feeders. They vary in color from 
yellowish, greenish, orangish, reddish or red, and some are only red in 
winter. Of medium size, they measure up to 0.80 mm. in length. Pear- 
shaped, with the narrow portion toward the rear, these mites possess 
more or less marked shoulders. The propodosoma is not separated or 
is only weakly separated from the hysterosoma by a weak suture. The 
dorsal body surface is usually arched, but is flat in Bryobia and Tetra- 
nycopsis. The skin is soft and has no plates. A pair of eyes is located 
on each side of the propodosoma. A peritreme is present and at times 
protrudes. The palpus has a thumb-claw complex. The chelicerae are 
fused at the base, forming the stylophore and the movable chela is 
highly modified into a long, whiplike, piercing organ which is charac- 
teristic for this group (and the Phytoptipalpidae), The tarsi have claws 
or modified pulvilli. The claws possess tenent hairs and are used in the 
generic classification of the group. Tarsus i usually has a pair of du- 



212 



Acarology 



plex sensory setae. No genital suckers are present. The males possess 
genitalia which are useful in species identification. 

The spider mites receive their name from their ability to spin a 
fine web over the leaves of the plant upon which they feed, and at 





Figure 162 Metatetranychus iilmi 
(Koch). Dorsum of female. 



Figure 163 Metatetranychus iilmi 
(Koch). Dorsum of male. 



times the entire plant may be covered by this webbing. Blauvelt 1945 
describes the silk glands as consisting of two groups, the tubular silk 
glands and the reniform silk glands, both of which empty into a 
common duct in the rostrum. Geijskes 1939 states that Tetranychus, 
Eotetranychus, Amphitetranychus and Schizotetranychus spin freely; 




Figure 164 Metatetranychus ulmi (Koch). Upper row, tip of tarsus, egg; lower 
row, tip of palpus, aedeagus. 



Trombidiformes 213 

Paratetranychus and Metatetranychus spin weakly; and Bryobia, Pe- 
trobia and Tetranycopsis do not spin. Grandjean 1948 believes the 
silk glands to be in the palps, opening on the palpal thumb through 
the broad, rounded, terminal "finger" or "spine." 

Genera: 

1. TetranychusT>uiouY, 1832 (= Epitetrany chus Zacher, 1916) 
Type. Tetranychus lintearius Dufour, 1832 

2. AUochaetophora McGregor, 1950 

Type. AUochaetophora calif ornica McGregor, 1950 

3. Amphitetranychiis Oudemans, 1931 
Type. Tetranychus viennensis Zacher, 1920 

4. AnatetranychusWoxnQYs\Qy, \940 

Type. Anatetranychus hakea Womersley, 1940 

5. Aplonobia Womersley, 1940 

Type. Aplonobia oxalis Womersley, 1940 

6. Apotetranychus OudQm2Lns, \93>l 

Type. Apotetranychus muscicola Oudemans, 1931 

7. Bryobia Koch, 1836 (= Schmiedleinia Oudemans, 1928) 
Type. Bryobia praetiosa Koch, 1836 

8. Eotetranychus Oudemans, 1931 
Type. Acarus telarius Linnaeus, 1758 

9. Eutetranychus Banks, 1917 (= Anychus McGregor, 1920) 
Type. Tetranychus banksi McGregor, 1914 

10. Eury tetranychus Oudemans, 1931 

Type. Tetranychus latus Canestrini and Fanzago, 1876 

11. Hystrichonychus McGregor, 1950 

Type. Tetranychus gracilipes Banks, 1900 

12. Linotetranus^erXcse, \9\0 

Type. Linotetranus cylindricus Berlese, 1910 

13. Metatetranychus Oudemans, 1931 
Type. Tetranychus ulmi Koch, 1836 

14. Monoceronychus McGregor, 1945 

Type. Monoceronychus californicus McGregor, 1945 

15. N eotetranychus Tragardh, 1915 

Type. N eotetranychus rubi Tragardh, 1915 

16. Oligonychus Berlese, 1886 (Oudemans 1938 states = Rhodaxes 

Kirchner, 1863) 
Type. Tetranychus minimus Tdirgioni-TozzeXii, 1878 (= Oligonychus 
brevipodus Berlese, 1886) 

17. Paratetranychus Zacher, 1913 

Type. Tetranychus ununguis Jacobi, 1905 

18. Petrobia Murray, 1877 (= Tetranobia Banks, 1917) 



214 Acarology 

Type. Acarus latens Mliller, 1776 (= Trombidium lapidum Hammer, 
1804) 

19. Platytetninychus Oudemans, 1931 

Type. Tetranychus gibbosus Canestrini, 1890 

20. Pseiidobryobia McGregor, 1950 

Type. Pseiidobryobia bakeri McGregor, 1950 

21. Septcmychus McGregor, 1919 

Type. Tetranychus tiimidus Banks, 1900 

22. Schizotetranychus Tragardh, 1915 (= Stigmaeopsis Banks, 1917 = 

Divarinychiis McGregor, 1930) 
Type. Tetranychus schizopus Zacher, 1913 

23. Simplinychus McGregor, 1950 

Type. Neotetranychus buxi Garman, 1935 

24. Tetranychina Banks, 1917 (= Tenuicrus Womersley, 1940) 
Type. Tetrany china apicalis Banks, 1917 

25. Tetranycopsis Canestrini, 1890 

Type. Tetranychus horridus Canestrini and Fanzago, 1876 

Discussion: Metatetranychus idmi (Koch) [known in this country 
as Paratetranychus pilosus (Canestrini and Fanzago)] can be used for 
illustrating one type of spider mite biology. The mite passes the winter 
as eggs, which are deposited on the branches and twigs, are bright red, 
and may be so numerous as to give the branches a reddish appearance. 
In the northwestern United States these eggs hatch in the spring, when 
the new leaves are appearing. The egg, which is stalked but without 
the guy wires found on legs of M. citri (McGregor), splits around its 
equator for most of its circumference, a small portion being left as a 
hinge. The upper half, or lid, is lifted by the six-legged larva, which 
crawls out, the lid usually springing back to its original position. The 
small, bright-red or orange larvae swarm to the young leaves and at 
once begin feeding. After a period of feeding, during which the larva 
moves about to some extent, it settles down, usually on the under side 
of the leaf near a vein or midrib, and remains quiescent for a time 
about equal to the feeding period. Afterward the skin becomes smooth 
and glossy in appearance and finally turns pearly white, an indication 
that the larva has loosened itself from the new skin underneath. Within 
a few hours the skin splits transversally across the dorsum, between 
. the second and third pair of legs, and the eight-legged protonymph 
emerges. The molted skins remain adhering to the leaf, and if numer- 
ous enough give the leaf a silvery appearance. The protonymphal stage 
is shorter than the larval stage, and the feeding and quiescent stages 
are repeated. The mite then molts and becomes a deutonymph, which 




Plate 2 Damage to citrus fruit and foliage by Metatetranychiis citri (Mc- 
Gregor). Damaged fruit and foliage is shown in upper row and normal material 
in lower row, (From A. M. Boyce, Insects and mites and their control. The 
Citrus Industry, Volume II, 1948. Courtesy of The University of California 
Press.) 



Trombidiformes 217 

is slightly longer than either larval or protonymphal stages. The fe- 
males become larger and more globose than the males during the 
deutonymphal stage and can thus be distinguished. The males com- 
plete each stage in a fraction of a day less than the females, the total 
in the Northwest for the immature stages averaging eight days for the 
males and nine days for the females. When the male emerges it runs 
about the leaf until it finds a quiescent female deutonymph. It then 
settles down beside the deutonymph to await emergence of the female. 
As soon as the nymphal skin of the latter splits across the back the 
male begins working at the posterior half of it with his fore legs and 
mouth parts. The female arches her back and within a few minutes 
her posterior legs are freed. She then backs out of the anterior half of 
the old skin and copulation takes place immediately, sometimes even 
occurring before the female has had time to free herself entirely from 
the nymphal skin. The male crawls under the female from the rear, 
the latter elevating the tip of her abdomen. The male clasps his front 
legs about her abdomen and his second pair of legs about her hind 
legs, and then curves the end of his abdomen upward and forward 
until it meets the end of the female's abdomen. Copulation lasts from 
ten to fifteen minutes. Eggs are laid within a day or two after emer- 
gence in hot weather, while in cool weather oviposition may begin 
several days or a week later. Eggs are laid on both surfaces of the leaf, 
usually along the midribs and veins and near the edges of the leaves.. 
These summer eggs hatch on an average in about eight to ten days. 
The number of generations per year depends on chmate and season. 
Four generations are reported in Sweden, probably six in Connecticut, 
and from six to eight in the Northwest. Overwintering eggs are de- 
posited over a rather long period, beginning about the middle of Au- 
gust, until the cold weather kills the mites or causes the leaves to drop, 
sometimes as late as November. Individual females of the sixth, sev- 
enth, and eighth broods may deposit these eggs. 

The life cycle of Metatetranychus citri (McGregor) is very similar 
to that of M. ulmi, except that in California the adults overwinter 
on the host and there may be from twelve to fifteen generations a 
year. 

Tetranychus bimaculatus Harvey overwinters chiefly as mature fe- 
males. During mild weather in the southern United States eggs are laid 
and considerable development may take place. This species overwin- 
ters on wild plants and in the spring, when the mites develop rapidly 
and the food plants become too crowded to support them properly. 



218 Acarology 

they migrate to other hosts, such as cotton. There appears to be a 
predominance of the females during the summer, but as cold weather 
approaches the numbers of the sexes become, more nearly equal. The 
female lives from seventeen days in midsummer to several months in 
winter, whereas the male is shorter lived. The female is not active, 
but the male, when not mating, moves rapidly about. The male is 
smaller and narrower than the female and the abdomen can be tele- 
scoped considerably, as during mating. Parthenogenesis, the giving 
birth to males by unfertilized females, has been reported. 

Little work has been done on the transmittal of plant diseases by 
the spider mites. Moskovetz 1940 reports a virus disease of cotton 
being transmitted by Tetranychus telarius (L.). 

Of the plant-feeding mites, the Tetranychidae are probably the most 
important economically. Hardly a plant is free from at least one spe- 
cies, and practically all species of the family are or appear to be poten- 
tial pests. The mites damage the plants by piercing the leaves with 
their stylet-like chelicerae and draining out the cellular material near 
the puncture. When the mite population is large the leaves may be 
killed and drop from the tree. Populations of red spiders may build 
up to fantastic numbers if left uncontrolled. In Porterville, California, 
Tetranychus pacificus McGregor has reproduced so rapidly in the 
summer on chinaberry (umbrella) trees that they were defoliated 
within a few days, and the dropping mites completely covered the 
entire surface of the ground as well as fence posts. The use of DDT 
for agricultural pests apparently has upset a spider mite-predator com- 
plex, causing the tetranychids to become serious problems in areas 
where they had been of no or of secondary importance. Little known 
or undescribed species are not only becoming pests, but some are build- 
ing up resistance to the newer acaricides. In many cases, however, no 
reason can yet be given for increased populations of these mites. 

There are many species of importance in the United States, but only 
a few are listed here. Metatetranychus iilmi (Koch) is distributed 
over continental Europe from Italy to Sweden and Norway, and from 
France to Russia. In the United States it is distributed generally along 
the Atlantic coast from Nova Scotia to North Carolina and west to 
Ontario, Michigan, Indiana, Tennessee, Kentucky, Wisconsin, Illinois, 
and Missouri. In the West it is found from British Columbia to cen- 
tral California and east to Idaho and northern Utah. The favorite food 
plants are the deciduous fruits, especially the plum, prune, apple, and 
pear, but this mite has been found on many other plants. M. citri 



Trombidiformes 219 

(McGregor) is one of the major pests of citrus in California. Although 
found in Florida, it is of little importance there, perhaps owing to cli- 
matic differences. 

Tetranychus bimaculatus Harvey (also known as T, telarius L.) 
occurs throughout the country and is a major pest of cotton in the 
southeastern United States as well as a pest of fruit trees and truck 
crops throughout the country. 

Bryobia praetiosa (Koch) is a pest of crops in the United States, 
being serious on almonds, peach, prune, alfalfa, clover, and peas. This 
species overwinters in the north in the egg stage and in southern re- 
gions as adults on clover and other plants. It is common in Europe. 

The Tetranychidae are not usually host specific, and on citrus, as 
well as on other plants, there are several species on the one plant. 
Tetranychus lewisi McGregor, T. yumensis McGregor, Metatetrany- 
chiis citri (McGregor), and Eutetranychus clarki McGregor are all to 
be found on citrus. 

References: 

Blauvelt, W. E. 1945. The internal morphology of the common red spider 
• mite {Tetranychus telarius Linn.) N. Y. (Cornell) Agr. Expt. Sta. 

Mem. 270. 
Cagle, L. R. 1949. Life history of the two-spotted spider mite. Virginia 

Agr. Expt. Sta. Tech. Bull. 113. 
Garman, P. 1940. Tetranychidae of Connecticut. Conn. (State) Agr. Expt. 

Sta. Bull. 431. 
., and J. F, Townsend. 1938. The European red mite and its control. 

Conn. (State) Agr. Expt. Sta. Bull. 418. 
Geijskes, D. C. 1939. Beitrage zur Kenntnis der Europaischen Spinnmilben 

(Acari, Tetranychidae) , mit Besonderer Berucksichtigung der Nieder- 

landischen Arten. Mededeelingen van de Landbouwhoogeschool 

42(4). 
Grandjean, F. 1948. Quelques caracteres des Tetranyques. Bull, du Mus. 

Ser. 2, 20(6):517-524. 
McGregor, E. A. 1950. Mites of the family Tetranychidae. Amer. Mid. 

Nat. 44(2):257-420. 
., and F. L. McDonough. 1917. The red spider on cotton. U.S. Dept. 

Agr. Bull. 416. 
Moskovetz, S. N. 1940. Plant virus diseases and their control. Trans. Conf. 

on Plant Virus Disease. Moscow 4-7/11. Moscow, Inst. MikrobioJ. 

Izd. Akad. Nauk U.S.S.R. 1941. 
Newcomer, E. L, and M. A. Yothers. 1929. Biology of the European red 

mite in the Pacific Northwest. U. S. Dept. Agr. Tech. Bull. 89, 



220 



Acarology 



Z 



Phytoptipalpidae Ewing, 1922 

(— Pseudoleptidae Oudemans, 1928; Trichadenidae Oudemans, 
Tenuipalpidae Sayed, 1950) 

Figures 165, 166 



1938; 



Diagnosis: These mites are reddish plant feeders of very small size 
(from about 0.20 to 30 mm. in length) and of various shapes. A 
suture may or may not separate the propodosoma and hysterosoma. 





Figure 165 Phytoptipalpiis paradoxus 
Tragardh. Venter of adult female. 
(After Sayed 1942) 



Figure 166 Brevipalpus carciinalis 
(Banks). Dorsum of female. 



The skin may be striated or it may have a reticulated pattern. There 
are two pairs of lenslike eyes, a few body setae, and no sensory setae 
present. The palpi are cylindrical, small, and simple without thumb- 
claw complex. The chelicerae are U-shaped, long, slender, needle-like, 
and protrusible as in the Tetranychidae. A stylophore (mandibular 
plate) is present. There are three or four pairs of legs in the adults. 
All tarsi have claws, tenent hairs and pulvilli. Tarsi i and ii have rod- 
like sensory setae. No genital suckers are present. The genital opening 
is transverse as in the Eriophyidae. 



Trombidiformes 221 

Genera: 

1. Phytoptipalpus Tragardh, 1904 

Type. Phytoptipalpus paradoxus Tragardh, 1904 

2. Brevipalpus Donnadieu, 1875 

Type. Brevipalpus obovatus Donnadieu, 1875 

3. Dolichotetranychus Sayed, 1938 

Type. Stigmaeus fioridanus Banks, 1900 

4. Pentamerismus McGregor, 1949 (= Aegyptobia Sayed, 1950) 
Type. Tenuipalpus erythreus Ewing, 1917 

5. Phyllotetranychus Sayed, 1938 (according to Vitzthum may be the 

same as Raoiella Hirst) 
Type. Phyllotetranychus aegyptium Sayed, 1938. 

6. Pseudoleptus BruydinX, \9\l 

Type. Pseudoleptus arechavalatae Bruyant, 1911 

7. Raoiella Hirst, 1924 (= Rondaniacarus Oudemans, 1938) 
Type. Raoiella indica Hirst, 1924 

8. Tegopalpus Womersley, 1940 

Type. Tegopalpus conicusV^omQrsXQy, 1940 

9. Tenuipalpus Donnadieu, 1875 

Type. Tenuipalpus palmatus Donnadieu, 1875 
10. Trichadenus Rondani, 1879 

Type. Trichadenus sericariae Rondani, 1879 

Discussion: The life history of this family may be illustrated by that 
of Brevipalpus inornatus (Banks) as worked out by McGregor 1916. 
The egg is thickly elliptical in outline, is about 96 ^ long by 67 ix wide, 
and is deposited with the long axis perpendicular to the leaf. The fe- 
male usually lays the egg in a crevice or abrasion, in old molted skins, 
or in the groove by the midvein. They are often closely packed in 
clusters of several hundred, each female laying approximately twenty 
eggs. In South Carolina during the summer the eggs hatch in about 
eight days and the six-legged larva emerges. The average larval dura- 
tion is 4.7 days. The larvae molt into protonymphs whose duration is 
about 4.5 days. The deutonymphal stage lasts about four days, the 
total being about twenty-one days. There are possibly six to seven 
generations per year in South Carolina, the mite being found through- 
out the entire year. All stages are more or less similar. 

The genus Phytoptipalpus Tragardh is a typical phytoptipalpid but 
lacks the fourth pair of legs. Sayed 1942 records it as having two 
"larval" stages before it attains sexual maturity. This genus, along 
with Tenuipalpus eriophyoides Baker nymph, indicates the phylo- 
genetic relationship between the Eriophyidae, which are elongate, an- 



222 Acarology 

nulate and with two pairs of legs, and the typical plant-feeding 
Tetranychidae. 

Although many members of this family appear to do little damage 
to the plants upon which they feed, some are of distinct economic 
importance. McGregor 1916 reports defoliation of privet throughout 
Florida, South Carolina, Alabama, Mississippi, and Louisiana by 
Brevipalpus inornatus (Banks). Green 1900 records a species as caus- 
ing serious damage to tea plants in Ceylon; the mites denude branches 
and even whole bushes of their leaves, terminal buds are damaged, 
and at times the bush is killed. Lewis 1944 found Brevipalpus lewisi 
McGregor scarring lemon fruit at Porterville, California; in parts of 
an infested grove, which had received no commercial spray treatment 
for about ten years, more than twenty-five per cent of the fruit 
was scarred, whereas in adjacent treated orchards these mites were 
hard to find. Jones et al. 1941 describes a Brevipalpus {B. phoenicis 
Geijskes) as sometimes causing serious damage to papaya fruits in 
Hawaii. T. H. The fruits develop gray, scaly, or cracked areas, most 
frequently at points where they are in contact with the trunk. This 
same species also damages citrus in Spain. Blanchard 1940 reports 
B. pseiidocimeatus (Blanchard) as a pest of citrus in Argentina. An- 
other is found damaging passion fruit in Australia. 

Tenuipalpus pacificiis Baker is a pest of orchids as is Brevipalpus 
australis (Tucker). Sayed 1942 reports Tenuipalpus granati Sayed as 
causing browning of the leaves in vineyards in Egypt; it has also been 
taken on leaves, branches and occasionally on fruits of pomegranates. 

Pseudoleptus and Dolichotetranychus are to be found in various 
salt grasses throughout the world; the two species at times cause dis- 
tortion of the grass heads. 

Rejerences: 

Baker, E. W. 1945. Mites of the genus Tenuipalpus (Acarina: Tricha- 

denidae). Proc. Ent. Soc. Wash 47(2):33-38. 
. 1948. A new trichadenid mite which further indicates a phylogenetic 

relationship between the Tetranychidae and Eriophyidae. Proc. Ent. 

Soc. Wash. 50(3) :59, 60. 
. 1949. The genus Brevipalpus (Acarina: Pseudoleptidae). Amer. 

Midland Nat. 42(2) :350-402. 
Blanchard, E, E. (1939) 1940. Tres acaros dahino para los cultivos argen- 

tinos. Rev. Fac. Agron. La Plata (3)24:11-18. 
Green, E. 1900. Tea-mites, and some suggested experimental work against 

them. Roy. Bot, Gard., Ceylon. Cir. 17(Ser. 1):202, 203. 



Trombidiformes 



223 



Jones, W. W., W. B. Storey, G. K. Parros, and F. G. Holdaway. Papaya 

production in the Hawaiian Islands. Bui. Hawaii Agri. Expt. Sta. 87: 

46. 
Lawrence, R. F. 1943. New South African mites of the genus Temiipalpiis 

Donnadieu (Tetranychidae). Trans. Roy. Soc. South Africa 30(1): 

35-48. 
Lewis, H. 1944. Injury to citrus by Tenuipalpiis mites. Calif. Citrograph 

29(4) :87. 
McGregor, E. A. 1916. The privet mite in the south. J. Econ. Ent. 9:556- 

560. 
. 1949. Nearctic mites of the family Pseudoleptidae. Mem. South. 

Calif. Acad, Sci. 3(2): 1-45. 
Planes, S. (1944) 1945. La roiia de los frutos citricos Bol, Patal. Veg. y 

Ent. Agr. 13:47-54. 
Sayed, M. T. 1942. Contribution to the knowledge of the Acarina of 

Egypt: II. The genus Tenuipalpus Donnadieu. Bull. Soc. Found 1^^' 

Ent. 24:93-113. 



Teneriffiidae Thor, 1911 

Figures 167, 168 

Diagnosis: These are medium-sized mites from 0.70 to 0.90 mm. 
long. The body is elongated with legs adapted for running. The in- 
tegument is lined, lacks a crista but has a propodosomal shield. There 

are two pairs of widely separated 
eyes. The anal opening is ventral 
(almost terminal) and the long 
genital opening has weak, sickle- 
like flaps with few setae and three 
pairs of weakly developed genital 
suckers. The legs are simply built 
and haired; the two ambulacral 





Figure 167 Aiistroteneriffia hirsti 
Womersley. Dorsum of female. 



Figure 168 Aiistroteneriffia hirsti 
Womersley. Distal portion of palpus. 



224 Acarology 

claws at least on legs i and ii are pectinate; legs iii and iv occasionally 
have a clawlike empodium. The rostrum is short and broad. The che- 
licerae are sickle-like, with two small setae on the dorsal surface of 
the basal segment. The palpus is five-segmented, thick, strongly bent, 
with a long tibial claw and weak setae. The palpal tarsus is almost 
rudimentary with setae of various lengths. Peritremes opening at base 
of chelicerae are present. 

Genera: 

1. Teneriffia Thor, 1911 (= Teneriffiola Strand, 1911) 
Type. Teneriffia qiiadripapillata Thor, 1911 

2. Austroteneriffia Womersley, 1935 

Type. Austroteneriffia hirsti Womersley, 1935 

3. Heteroteneriffia Hirst, 1926 

Type. Heteroteneriffia marina Hirst, 1926 

4. Neoteneriffiola Hirst, 1924 

Type. Neoteneriffiola luxoriensis Hirst, 1924 

5. Parateneriffia Thor, 1911 

Type. Parateneriffia bipectinata Thor, 1911 

Discussion: Heteroteneriffia marina Hirst, 1926 was collected in 
Malaya under rocks and stones on a rocky bank which was submerged 
at half-tide every day and at full tide was under four to six feet of 
water. At low tide there was a permanent pool of sea-water about 
twenty feet wide between the bank and the shore. The mites moved 
rapidly and were hard to catch. Other species and genera have been 
described from such widely divergent localities as the Island of Ten- 
eriffe, Paraguay, Egypt, and Australia. 

The structure of the mites indicates a predaceous habit. 

Reference: 

Womersley, H. 1935. On the occurrence in Australia of Acarina of the 
family Teneriffiidae (Trombidoidea) Rec. South Austral. Mus. 5: 
333-338. 

Pseudocheylidae Oudemans, 1909 

Figure 169 

Diagnosis: The pseudocheylids are colorless or reddish, small to medi- 
um-sized mites from 0.23 to 1.1 mm. long. They are more or less elon- 
gated and somewhat rhombic, with a strong furrow between the propo- 



Trom b idiform es 



225 



dosoma and the hysterosoma. The propodosomal shield is either weak 
or entirely lacking as is usually the case. The peritreme is present at the 
base of the chelicerae. There are two pairs of sensory setae on the pro- 
podosoma. Two pairs of lenslike eyes may be found on each side of the 
propodosomoa {Pseudocheylus), or two pairs of pigment spots with 
a mutual cornea (Neocheylus), or 
there may be no eyes. The palpi are 
short and usually somewhat thicker 
than the legs. The palpal femur is 
longer than the other segments and 
thickened on the outer side so that 
the palpi are forceps-like. The pal- 
pal tibia has a strongly bent claw, 
and the ventral palpal tarsus is 
weak (or entirely gone?). Tarsi of 
the legs have either a long stalked 
triangular caruncle or sucker and 
no claws {Pseudocheylus, Neo- 
cheylus), or have a bell-like car- 
uncle or lobe between two claws 
(Tarsocheylus) , or lack an empo- 
dium and have normal but very 
small claws on tarsi i and comblike 
claws on the other tarsi {Stigmo- 

cheylus). No genital suckers are Figure 169 Pseudocheylus (Anop- 

present. The genus He.erocheylus ^^l ^aT Berf/seT^loT""" 
has only one pair of propodosomal 

sensory setae. Tarsi i lack ambulacra, but ii, iii, and iv have caruncles or 
lobes only. Tragardh 1950 has divided these mites into two subfamiUes. 




Key to the Pseudocheylidae 

(from Tragardh) 

1. Chelicerae stylet-like; palps with large, sharply pointed, dentate 
terminal tooth and varying number of comb-shaped or sickle- 
shaped setae; all legs with claws Pseudocheylinae 

Chelicerae with strongly curved, sharp terminal tooth of the same 
type as in the larvae of the Trombidiidae. Palps with blunt, eden- 
tate terminal tooth, no comb-shaped or sickle-shaped setae. Legs 
I antenniform, legs n-iv with tooth-shaped, subterminal bristle and 
large, disk-shaped empodium Heterocheylinae 



226 Acarology 

Pseudocheylinae Tragardh, 1950 
Genera: 

1. Pseudocheylus Berlese, 1888 

a. Pseudocheylus s. str. (= Rhagina Womersley, 1935) 
Type. Pseudocheylus biscalatus Berlese, 1888 

b. Anoplocheylus Berlese, 1910 

Ty^Q. Pseudocheylus {Anoplocheylus) europaeus Bqv\q?,q, 1910 

2. Neocheylus Tragardh, 1906 

Type. Neocheylus natalensis Tragardh, 1906 

3. Stigmocheylus Berlese, 1910 

Type. Stigmocheylus brevisetus Berlese, 1910 

4. Tarsocheylus Berlese, 1904 

Type. Tarsocheylus paradoxus Berlese, 1904 

Heterocheylinae Tragardh, 1950 
Genus: 

Heterocheylus Lombardini, 1926 

Type. Heterocheylus fusiformis Lombardini, 1926 

Discussion: This is a small family consisting of only a few described 
species. A single species has been described from the United States, 
Pseudocheylus americanus (Ewing) , which was taken under the bark of 
a hard maple tree at Urbana, Illinois. Another species, Pseudocheylus 
biscalatus Berlese, was collected under the bark of trees in Paraguay 
and Brazil in South America. Neocheylus natalensis Tragardh is from 
damp moss, Natal, South Africa. Pseudocheylus protea (Womersley) 
is from moss, Australia. The other genera are represented by species 
from soil, moss, humus, and rotten debris in Italy. The family as a 
whole appears to be predaceous, with the exception of Heterocheylus 
which is an ectoparasite of arthropods. 

Reference: 

Tragardh, I. 1950. Description of a new species of Heterocheylus Lom- 
bardini from Africa, with notes on the classification of the Pseudo- 
cheyletidae. Ent. Tidskrift 71, hft. 2:104-110. 

Anystidae Oudemans, 1902 

Figure 170 

Diagnosis: Of red or reddish color, the anystids are medium-sized 
mites from 0.55 to 1.35 mm. long. They have a soft integument and 



Trombidiformes 



227 



may or may not possess a propodosomatic shield (actually a lack of 
or differentiation in skin striations rather than a sclerotization). No 
suture is present between the propodosoma and the hysterosoma. The 
peritreme, at times freely protruding and located at the base of the 
chelicerae, is present. The rostrum is short and conehke. A movable 
chela which is distal and hook- 
like is also present. The palpal 
tibia has one to three internal 
claws and the palpal tarsus is lo- 
cated disto-ventrally on the tibia. 
A smooth tubercle-like projection 
on the anterior portion of the pro- 
podosoma bears a pair of sensory 
setae; the propodosoma has a pair 
of sensory setae. The legs radiate 
from the body and the coxae are 
in one or two closely separated 
groups. All tarsi are either entire or divided into many segments; the 
tarsi have two claws which may be combed, toothed, or pilose and 
which have a clawlike, brushlike or bell-like empodium. There are no 
genital suckers. There are two subfamilies. 

Key to the Anystidae 

1. Short, broad; with two pairs of eyes; palpal tibia with three claws 

Anystinae 

Longer than broad; with one to two pairs of eyes; palpal tibia with 
one smooth claw or two feathered claws Erythracarinae 




Figure 170 Anystis baccarum (Lin- 
naeus). Dorsum of female. (After 
Oudemans 1936) 



Anystinae Oudemans, 1936 



Genera: 



1. Anystis v. Heyden, 1826 (= Actineda Koch, 1836) 
Type. Trombidium cornigerum Hennann, 1804 

2. Autenriethia Oudemans, 1936 
Type. Actineda velox Berlese, 1905 

3. Barella Oudemans, 1936 

Type. Anystis sinensis Berlese, 1923 

4. Scharfenbergia Oudemans, 1936 
Type. Actineda hilaris Koch, 1836 

5. Snartia Oudemans, 1936 

Type. Snartia nepenthus Oudemans, 1936 



228 Acarology 

6. Tencateia Oudemans, 1936 

Type. Tencateia besselingi Oudemans, 1936 

7. Walzia Oudemans, 1936 

Type. Actineda antiguensis Stoll, 1886 

Erythracarinae Oudemans, 1936 
Genera: 

1. Erythracarus Berlese, 1903 

Type. Tromhidium parietinum Hermann, 1804 (= Erythraeus comes 
Berlese, 1886) 

2. Absoloniana Willmann, 1940 

Type. Absoloniana diversipes Willmann, 1940 

3. Anandia Hirst, 1927 

Type. Anandia alticola Hirst, 1927 

4. Bechsteinia Oudemans, 1936 

Type. Bechsteinia schneideri Oudemans, 1936 

5. Chabrieria Oudemans, 1936 

Type. Tarsotomus terminalis Banks, 1916 

6. Chaussieria Oudemans, 1937 (= Schellenbergia Oudemans, 1936, 

nom. praeocc.) 
Type. Erythraeus domesticus Koch, 1847 

7. Erythrocheyhis Berlese, 1903 

Type. Pseudocheylus erythraeoides Leonardi, 1901 

8. Siblyia Oudemans, 1936 

Type. Erythraeus ignipes Duges, 1834 

9. Tarsolarkus Thor, 1912 

Type. Tarsolarkus articulosus Thor, 1912 
10. Tarsotomus Berlese, 1882 

Type. Erythraeus hercules Berlese, 1882 

Discussion: These are long-legged, fast moving mites, predaceous on 
other mites and many small insects. They are to be found on plants, 
tree leaves, branches, and grass. Although they are not usually abun- 
dant, they occasionally may be found in great numbers. Anystis agilis 
(Banks) is described from the United States and Walzia antiguensis 
(Stoll), a Venezuelan species, has been found in Florida. 

The larval, nymphal, and adult stages are similar; two nymphal 
stages are known. The mites apparently have the power of spinning 
and the young can enclose themselves in a cocoon (nymphochrysalis 
or teleiochrysalis). Banks has found freshly molted specimens encased 
in little silken white cocoons. 



Trombidi formes 



229 



Reference: 

Oudemans, A. C. 1936. Neues uber Anystidae (Acari). Archiv. f. Natur- 
gesch. neue folge 5:364-446. 

Myobiidae Megnin, 1877 

Figures 171, 172 

Diagnosis: These are small to medium-sized mites that are unar- 
mored and have striated skin and peritremes. The chelicerae are mi- 
nute and stylet-like. The palpi are simple, minute, and not used for 
grasping; they may or may not have a claw and if a thumb is present 





Figure 171 Myobia muscu- 
liniis (Schrank). Dorsum of 
female. 



Figure 172 Syringophilus cohimbae Hirst. 
Dorsum of female. (After Hirst 1922) 



it is hard to see. The first pair of legs may be modified for grasping 
hairs; the other legs have one or two claws. The male genital opening 
may be dorsal. This is a rather heterogeneous group of mites and may 
be further separated upon study. Harpirhynchus, Ophioptes, Picobia, 
Psorergates, and Syringophilus may form a distinct family intermediate 
between the Myobidiidae and Cheyletidae but probably closer to the 
latter. 



230 Acarology 

Genera: 

1. My o/) /Vz V. Hey den, 1826 

Type. Pediculus musciili Schrank, 1781 

2. Amorphacarus Ewing, 1938 

Type. Myobia elongata Poppe, 1 896 

3. Calcarmyohia Radford, 1948 

Type. Myobia rhinolophia Radford, 1940 

4. £"<7^/^a Jameson, 1949 

Type. Eadiea condylume Jameson, 1949 

5. Eutalpacanis Jameson, 1949 

Type. Eutalpacanis peltatus Jameson, 1949 

6. Ewingana Radford, 1948 

Type. Ewingana bispinosa Radford, 1 948 

7. Eoliomyobia Radford, 1948 

Type. Myobia chiropteralis Michael, 1884 

8. Harpirhy nchus Megn'm, 1877 (= Harpicephalus CsLnesirinl 1885 = 

Sarcopterinus Railliet, 1893 = Sarcopterus Giebel, 1871 — Sar- 
coborus Oudemans, 1904) 
Type. Sarcoptes nididans Nitzsch, 1818 

9. Neomyobia Radford, 1948 

Type. Myobia roUinati Poppe, 1 908 

10. 0/?/7/o/7r£'5 Sambon, 1928 

Type. Ophioptes parkeri Sambon, 1928 

11. P/co/?/fl Haller, 1878 

Type. Picobia heeri Haller, 1878 

12. Protomyobia Ewing, 1938 

Type. Myobia claparedei Poppe, 1896 

13. Psorergates Tyrrell, 1883 

Type. Psorergates simplex Tyrrell, 1883 

14. /?«(^/orJ/<:/ Ewing, 1938 

Type. Myobia ensifera Poppe, 1896 

15. 5yrm^op/z//w5 Heller, 1880 

Type. Syringophilus bipectinatiis Heller, 1880 

Discussion: The mites forming the Myobia complex are found on 
mammals of three orders — Rodentia, Insectivora, and Chiroptera. 
This group of mites has legs i greatly modified for hair clasping. Ac- 
cording to Ewing 1938 they feed at the bases of the hairs on the 
secretions in the hair follicles and seldom, if ever, suck blood. Grant 
1942, working with Myobia musculi (Schrank), has observed feeding 
and states, "Feeding appears to occur at other places than in the hair 
follicles, at least the beak seems often to be inserted into the skin 



Trombidi formes 231 

where no hair can be seen to arise even with the aid of a dissecting 
microscope. It may be mentioned that what appeared to be red blood 
corpuscles were observed in the oral tube of one specimen." Jameson 
1948 states that Myobia simplex Ewing has been found full of blood. 
Skidmore 1934 found Radjordia ensifera (Poppe) (= Myobia ratti 
Skidmore) causing injury to white rats. He states, "These rats were 
scratching themselves about the head, nose and neck. Many had small 
dry scabs on the head, about the ears, and upper sides of the neck. 
Some had bloody scabs due to bleeding caused by severe scratching." 
These mites are probably distributed throughout the world. In Aus- 
tralia Psorergates ovis Womersley, 1941 is parasitic on sheep produc- 
ing a chronic irritation of the skin along the sides and flanks of the 
body. The genus Syringophilus contains species which are to be found 
inside the quills of bird feathers in North America and Europe: they 
are believed to feed on the internal cones of the feathers. Harpirhyn- 
chus nidulans (Nitzsch) lives in colonies in the follicles of feathers and 
causes tumors or cysts in the skin of the host; the mite is to be found 
on numerous birds including the pigeon. The genus Ophioptes con- 
tains mites which are parasitic on South American snakes. They live 
in small pits which they produce in the heavily cornified layer of the 
snake scales. Ewing 1933 described a species which forms pits in the 
scales; both Ewing and Sambon described two forms — one is a sack- 
like nymph without legs, and within this swollen nymphal form is a 
fully formed, eight-legged individual which Sambon described as a 
male and which Ewing believed to be a nymph or a female; examina- 
tion of the type in the United States National Museum shows the form 
to be an adult but with the sex unknown. The life cycle is otherwise 
unknown. 



Rejerences: 

Ewing, H. E. 1938. North American mites of the subfamily Myobiinae, 
new subfamily (Arachnida). Proc: Ent. Soc. Wash. 40(7) : 180-197. 

Grant, D. C. 1942. Observations on Myobia musculi (Schrank) (Arach- 
nida: Acarina: Cheyletidae). Microentomology 7(3):64-76. 

Jameson, E. W. 1948. Myobiid mites (Acarina: Myobiinae) from Shrews 
(Mammalia: Soricidae) of Eastern North America. J. Parasitol. 34 
(4):336-342. 

. 1949. Myobiid mites (Acarina: Myobiidae) from Condylura cristata 

(Linnaeus) Sind Neurotrichus gibbsii (Baird) (Mammalia: Talpidae). 
J. Parasitol. 35(3) :423-430. 



232 



Acarology 



Radford, C. D. 1934. Notes on the genus Myohia. North Western Natural- 
ist 356-364. 1935: 248-258, 1936 a:34-39. 1936 b: 144-151. 

. 1948. A revision of the fur mites Myobiidae (Acarina). Bull. Paris 

Mus. d'Hist. Nat. Ser. 2, 20(5) :458-464; (6) :525-531. 

Womersley, H. 1941. Notes on the Cheyletidae (Acarina, Trombidoidea) 
of Australia and New Zealand with descriptions of new species. Rec. 
South Austral. Mus. 7(l):51-64. 



Cheyletidae Leach, 1814 

Figure 173 

Diagnosis: The cheyletids are yel- 
lowish or reddish, small to medium- 
sized mites measuring from about 
0.20 to 0.80 mm. in length. Their body 
is oval, plump, and in the feather- 
inhabiting mites, elongate. The propo- 
dosoma and the hysterosoma are 
usually plainly delineated and usually 
they have one or more dorsal shields. 
Lenslike eyes may be present or lack- 
ing. The dorsal body setae are simple, 
serrate, rodlike, or clavate. A strong 
peritreme which more or less frames 
the gnathosoma is present. The cheli- 
cerae are short and stylet-like for 
piercing while the palpi are large and 
pincer-like for grasping. The palpal 
thumb is short and may or may not 
have a comb and sickle-like setae. A 
large terminal claw, usually toothed, is located on the palpal tibia. 
The tarsi of the legs have two claws and an empodium (tarsus i of 
Cheletogenes has no claws or pulvillus; tarsus i of Cheletomorpha 
lacks claws but has a pulvillus) . There are no genital suckers. The geni- 
tal opening of the male is in some cases dorsal but usually posterior and 
ventral. 




Figure 173 Cheletogenes ornatiis 
(Canestrini and Fanzago). Dor- 
sum of female. 



Genera: 

1. Cheyletus\.2iirQ\\\Q, \196 

Type. A cams eruditus Schrank, 1781 



Trombidiformes 233 

2. Acaropsis Moquin-Tandon, 1862 

Type. Jyroglyphus mencourti Moquin-Tandon, 1851 

3. Chelacaropsis Baker, 1949 

Type. Chelacaropsis moorei Baker, 1949 

4. Cheletogenes Oudemans, 1905 

Type. Cheyietus ornatus Canestrini and Fanzago, 1876 

5. Cheletoides Oudemans, 1904 

Type. Syringophilus uncinatus Heller, 1880 

6. Cheletomimus Oudemans, 1904 

Ty^Q. Cheletes berlesei Oudemans, 1904 (= Cheletomimus trux 
Oudemans, 1904) 

7. Cheletomorpha Oudemans, 1904 

Ty^Q. Acarus lepidopterorum Shaw, 1794 (= Cheyietus venustis- 
simus Koch, 1839) 

8. Cheletophanes Oudemans, 1904 

Type. Cheyietus montandoni Berlese and Trouessart, 1889 

9. Cheletophyes Oudemans, 1914 

Type. Cheletophyes vitzthumi Oudemans, 1914 

10. Cheletopsis Oudemans, 1904 

Type. Cheyietus norneri Poppe, 1888 

11. Cheletosoma Oudemans, 1905 

Type. Cheletosoma tyrannus Oudemans, 1905 

12. Chelonotus Berlese, 1893 

Type. Chelonotus selenirhynchus Berlese, 1893 

13. Cheyletia Haller, 1884 

Type. Cheyletia laureata Haller, 1884 

14. Cheyletiella C?inQsiYim, 1886 (= Ewmge//a Vail and Augustson, 1944) 
Type. Cheyietus parasitivorax Megnin, 1878 

15. Eucheyletia Baker, 1949 

Type. Eucheyletia bishoppi Baker, 1949 

16. Eutogenes Baker, 1949 

Type. Eutogenes foxi Baker, 1949 

17. Neoeucheyla Radford, 1950 (= Eucheyla Berlese, 1913. nom. 

praeocc. ) 
Type. Cheyletia {Eucheyla) loricata Berlese, 1913 

18. Neocheyletiella Baker, 1949 

Type. Neocheyletiella rohweri Baker, 1949 

Discussion: These mites develop normally from egg, larval, and 
nymphal stages to adults. Nymphs may have more dorsal plates than 
adults, in the genus Cheyietus the male often is dissimilar from the 
female in the nature of the gnathosoma. In these species the palpi are 
greatly elongated and have few or no basal teeth on the palpal claw; 



234 Acarology 

an aedeagus is present, the larger female genital opening is lacking, 
and the sensory organ on tarsus i of the male is greatly enlarged. In 
Cheyletiella parasitivorax (Megnin) the male genital opening is dor- 
sal. In other genera where the two sexes are known the males are more 
or less similar to the females, varying in the characteristics mentioned 
above. Ewing 1912 has studied the life cycle of a Cheyletus. Eggs are 
laid near each other but not in clusters and the female remains near 
them for some time after oviposition has ceased. One female laid 
twenty-five eggs over a six-day period, another twenty-two eggs in 
two days and another laid only a single egg. At laboratory tempera- 
ture, on an average, the duration of the incubation period was 4.3 
days, the larval stage 7.66 days, the first nymphal stage 4.5 days, the 
second nymphal stage at least 5 days, and the adult stage 13 days. 
The larva is similar to the aduh but has only six legs; the nymphs are 
likewise similar to the adult but have four pairs of legs. Ewing found 
that the young mites prefer eggs of other mites such as Acaridae with 
which they are associated. In the milled wheat samples he found that 
about 95 per cent of the acarids were killed in a short time by these 
cheyletids. Rodionov and Furman 1940 in a study of Cheyletus 
eniditus (Schrank) for control of granary mites {Acarus siro L., 
Tyrophagus castellanii Hirst and Glycyphagus destructor (Schrank ) , in 
Russia found that the cheyletids are not of great value in the control 
of grain mites in granaries and that their presence only lowers the 
purity of the grain. Their developmental period is longer than that of 
the grain mites, and although they are more resistant to desiccation, 
they are more susceptible to hydrocyanic gas. The strongly armored 
hypopial stages of the grain mites were not attacked by the cheyletids. 
The Cheyletidae, as a whole, are free-living predators, although 
some are to be found in bird feathers, in squirrel, rabbit, or cat fur, 
and sometimes appear to injure the host. The free-living forms are to 
be found in association with infestations of other mites such as the 
Acaridae and Tetranychidae, and with scale insects, but as yet they 
do not appear to be of great importance in controlling mites or insects. 
Because of their free-living habits many species are world-wide in 
distribution. 

References: 

Baker, E. W. 1949. A review of the mites of the family Cheyletidae in the 
United States National Museum. Proc. U. S. Natl. Mus. 99(3238): 
267-320. 



Trombidiformes 



235 



Cooper, K. W. 1946. The occurrence o\ the mite, Cheyletiella parasitivorax 

(Megnin) in North America, with notes on its synonymy and 

"parasitic" habits. J. Parasitol. 32(5) :480-482. 
Ewing, H. E. 1912. The life history and habits of Cheyletus seminivorus 

Packard. J. Econ. Ent. 5(5) :416-420. 
McGregor, E. A. 1944. A new potential enemy of the bud mite. CaUf. 

Citrograph 30(2) :53. 
Olsen, S. J., and H. Roth. 1947. On the mite Cheyletiella parasitivorax, 

occurring on cats, as a facultative parasite of man. J. Parasitol. 33 

(5): 444-445. 
Oudemans, A. C. 1906. Revision des Cheletines. Mem. Soc. Zool. de 

France 19:36-219. 



Demodicidae Nicolet, 1855 

Figures 174, 175 

Diagnosis: The demodicids are weakly colored, very small mites 
from 0.10 to 0.39 mm. long. They are vermiform, annulate, and eight- 
legged. The legs are short, stumpy, five-segmented, and located on the 
anterior portion of the body. The chelicerae are stylet-like as in the 





Figure 174 Demodex miiscardini Figure 175 Demodex muscardini 

Hirst. Dorsal view of male. (After Rirst. Ventral view of female. (After 
Hirst 1919) Hirst 1919) 

Cheyletidae. A capitulum which covers the palpi and the chelicerae is 
present. The palpi are three-segmented and the distal segment has four 
or five rodlike setae. There is a pair of minute openings located on the 
venter of the capitulum near the base. The female genital opening is 
situated between or behind coxae iv, while the male genital opening is 
dorsal in the center of the podosoma. No genital suckers are present. 



236 Acarology 

Genus: 

Demodex Owen, 1843 

Type. Acanis foUiculorum Simon, 1842 

Discussion: Demodex muscardini Hirst, a parasite of the dormouse, 
Muscardinus avellanarius, illustrates a complete life cycle of these 
mites. The eggs hatch into a larva which is very much like the early 
nymphal stage, except that there are three instead of four pairs of legs 
which consist of a chitinous plate or epimeron; each epimeron bears 
a pair of very minute and inconspicuous denticulate tubercles. The 
protonymph has four pairs of legs or epimera, each bearing two tiny 
but distinct tubercles of equal size, each with three or four minute but 
distinct denticles. There are four pairs of curious epidermal structures 
present nearer the middle of the ventral surface of the body. These are 
semicircular in shape, and the posterior margin is curved and furnished 
with sharp denticles. The deutonymph has the appendages or legs simi- 
lar to those of the protonymph, but they are more leglike with several 
segments visible and with two clusters of denticles present. The four 
pairs of semicircular structures in the ventral surface are present but 
are much smaller. The adult has the genital opening, five-segmented 
legs, and has lost the semicircular structures on the ventral surface of 
the body. 

Hirst 1919 gives an excellent review of the family from which the 
following information is taken. Demodex foUiculorum Owen, which is 
to be found in the pores of man, especially around the nose and eye- 
lids, has been implicated in various skin diseases. It has been noted, 
however, that these mites occur in normal as well as diseased tissue 
and are to be found infesting most people. It is now believed to be of 
no importance in man. Like the following species it is more or less 
world-wide in distribution. D. cams Leydig is present in the follicular, 
demodectic, or red mange of dog. In typical cases the mite is to be 
found in great numbers in association with a bacterium {Staphylococcus 
pyogenes albus or some allied form), which is the actual cause of the 
disease. The mite plays an important role in that it dilates the follicles 
and sweat glands and even possibly carries the germ into the pores. 
The mange may be pustular, accompanied by various crusts; it may 
be a "squamous affection with numerous epidermal pellicles. In a 
typical case there are small hairless patches, together with reddish 
pimples and pustules, skin hot and thickened in the affected places." 
There is a foul and disgusting odor accompanying this mange. The 



Trombidiformes 237 

presence of the mite distinguishes this mange from sarcoptic mange 
or fungus infections. D. equi RaiUiet, aUhough present on horses free 
of any disease, can also cause a "pathological condition of the skin, 
characterized either by pruritus, varying greatly in intensity, or by 
definite lesions. The coat is poor, with the hair very sparse in places." 
The disease usually commences on the saddle or neck of the animal 
but does not appear to be infectious. In the advanced stage pustules 
are present and the skin thickens. D. phylloides Csokor "causes a pus- 
tular skin disease in pigs, the pustules varying from the size of a grain 
of sand to a walnut." "Sometimes they may become confluent, and 
may rupture and cause sores and ulcers on the skin." They are to be 
found only where the skin is fine in texture, spreading "from the snout 
over the neck and under part of the chest and abdomen, and over the 
flanks and inner parts of the legs." Usually the general health of the 
animals is not affected. D. bovis Stiles causes nodules or pustules in 
cattle, these pustules varying in size from a head of a pin to as large 
as a hen's egg. They are to be found around the ears, sides, shoulders, 
and intercrural space. Various stages of development are to be found 
in the cheesy or fluid contents of the nodules. The disease appears to 
be infectious but does not seem to affect the general health of the ani- 
mal. However, holes caused by these mites reduce the value of the 
hides. Other species have been found on sheep, hedgehogs, field mice, 
cats, rabbits, voles, and rats and are probably to be found on many other 
hosts. 

References: 

Hirst, S. 1919. The genus Demodex Owen. Brit. Mus. (Nat. Hist.) 

Studies on Acari No. 1. 
. 1922. Mites injurious to domestic animals. Brit. Mus. (Nat. Hist.) 

Econ. Series No. 13. 
Lombardini, G. 1942. Contributo alia conoscenza della morfologia dei 

Demodicidae. Chiave analitica del genere Demodex Owen. Redia 28: 

89-102. 

Erythraeidae Oudemans, 1902 

Figures 176, 177 

Diagnosis: The adults of this family are reddish, predaceous mites 
with legs adapted for running. The larvae are heteromorphic, lack 
urstigma, and are parasitic on arthropods. The adult body is oval and 



238 



Acarology 



arched with large numbers of setae. A shallow furrow separates the 
propodosoma from the hysterosoma. The propodosoma has a median, 
longitudinal crista metopica (Vitzthum lists Fallopia and Neosmaris 
as exceptions) which may reach posteriorly to the middle of the dor- 
sum. There are two sensillary areas on crista; the anterior one is often 
far forward on a "nose," while the posterior one is usually on the 










Figure 176 Leptiis hirtipes Berlese. figure 777 Leptiis tene brans Vitz- 
Dorsum of female. (After Vitzthum thum. Larva, (After Vitzthum 1926) 
1926) 



posterior end of the crista; the sensillary areas each have a pair of 
sensory setae. In mites lacking the crista, the sensory setae are located 
in a corresponding location. Either one or two pairs of lenslike eyes 
are present. Coxae i and ii and in and iv are in two groups; the legs 
are long, slender and have six movable segments; the tarsi have two 
claws, but no empodium. Five movable segments comprise the palpi 
and the palpal tibia has a strong claw. The palpal thumb is usually 
pear-shaped but sometimes ball-like. The chelicerae are unsegmented, 
stylet-like, very long, capable of being withdrawn into the body, and 
usually toothed distally. No genital suckers are present. 



Trombidiformes 239 

Genera and subgenera: 

1. Erythraeiis Latreille, 1806 (= Rhyncholophus Duges, 1834) 

a. Erythraeiis s. str. 

Type, Acarus phalcmgioides DeGeer, 1778 

b. Corerythrolophiis Radford, 1950 (= Erythrolophiis Berlese, 1920, 

nom. praeocc.) 
Type. Erythraeiis {Erythrolophiis) froggatti Berlese, 1920 

c. Ctenerythraeus Berlese, 1918 

Type. Erythraeus {Ctenerythraeus) trombidioides Berlese, 1918 

d. Ptilolophiis Berlese, 1916 

Type. Erythraeiis {Ptilolophus) claviger Berlese, 1916 

2. Balaustium v. Heyden, 1826 (= Monotrombidiiim Krauss, 1925) 
Type. Trombidium murorum Hermann, 1804 

3. Bochartia Oudemans, 1910 

Type. Bochartia kuyperi Oudemans, 1910 

4. Caecidisoma Berlese, 1888 

Type. Caecidisoma tuberculatum Berlese, 1888 

5. Callidosoma Womersley, 1936 

Type. Caeculisoma ripicola Womersley, 1934 (larva) 

6. ClaverythraeusTr'?igkrdh,\9'il 

Type. Claverythraeus mongolicus Tragardh, 1937 

7. Erythrellus Southcott, 1946 

Type. Erythrellus imbricatus Southcott, 1946 

8. Erythroides Southcott, 1946 

Type. Erythraeus serratus^ornQTsXty, 1936 

9. Erythrombium Berlese, 1910 

Type. Erythrombium eusisyrum Berlese, 1910 

10. Euplatylophus Radford, 1950 (= Platylophus Berlese, 1910, nom. 

praeocc. ) 
Type. Platylophus argasoides Berlese, 1910 

11. Fallopia Oudemans, 1905 (= Microsmaris Hirst, 1926) 
Type. Rhyncholophus poriferus Kramer, 1898 

12. Hauptmannia Oudemans, 1910 

Type. Achorolophus longicollis Oudemans, 1910 

13. Leptus Latreille, 1795 (= Achorolophus Berlese, 1891) 
Type. Pediculus coccineus Scopoli, 1763 

14. Lucasiella Banks, 1910 

Type. Rhyncholophus plumipes Koch, 1856 

15. Neosmaris Hirst, 1926 

Type. Neosmaris novaezealandiae Hirst, 1926 

16. Parawenhoekia Paoli, 1937 

Type. Parawenhoekia dectici Paoli, 1937 

17. Parerythraeus Southcott, 1946 



240 Acarology 

Type. Parerythraeus gregoryi Southcott, 1946 
18. Sphaerolophiis Berlese, 1910 

a. Sphaerolophiis s. str. 

Type. Rhyncholophiis globiger Berlese, 1885 

b. Cavannea Berlese, 1910 

Type. Rhyncholophus cavannae Berlese, 1885 

c. Eupodolophiis Berlese, 1914 (= Fessoniella Hirst, 1924) 
Type. Sphaerolophiis {Eupodolophiis) chiibbi Berlese, 1914 

Grandjean 1947 has separated the Erythraeidae into two families — 
Erythraeidae and Balaustiidae — but this arrangement is not followed 
here. 

Discussion: The larvae of these mites are parasitic on insects much 
as the larvae of the Trombiculidae are parasitic on vertebrates. In one 
case Lawrence 1940 found as high as 400 larvae of Erythraeus swa~ 
zianiis Lawrence on a locust. Usually the number infesting an arthro- 
pod is much smaller. Lawrence states that the "larvae seem to attach 
themselves by the mouth-parts at all stages" and some of the molted 
skins can be found still adhering to the host. Most of the larvae are 
attached to the undersurface of the wings, and even to the tympanic 
membrane within the organ and under the rim of the opening. They 
are rarely found on the legs. Leptus atticolus Lawrence was taken 
from the legs of a spider, Saitis sp., Attidae, in Natal, South Africa. 
A mite identified as a Leptus sp. has been reared from lizards in Bou- 
gainville in the South Pacific. This is the first record of an erythraeid 
being parasitic on a vertebrate. Most species are known either from 
the larva or the adult, very few having the different stages correlated. 
Adults are free-living predators and may be found on foliage, in 
humus or among leaves, and on the shore and sands. Balaustium 
aonidaphagus (Ebeling) is reported as a predator of the red scale on 
citrus in California. Ebeling 1934 states, "these mites are not ordi- 
narily abundant and the writer has found them only in certain groves. 
As high as thirty mites were found on a single tree, but ordinarily only 
one or two, if any, are found. They may also be seen running about, 
on the ground beneath the trees, which may, in part, be due to the 
difficulty they experience in clinging to the foliage." They are cannibal- 
istic and if a number are left together in a sealed container invariably 
only one live mite will remain after a day or two. "The writer once 
observed a mite thrusting its mandibles and finally its entire cephalo- 
thorax beneath the armor of a red scale and feeding on the body ol 



Trombidiformes 241 

the insect. These mites also prey on red scale crawlers and other small 
insects and mites. If more abundant they might be an important enemy 
of the red scale." 

An interesting erythraeid mite is Ptilophus namaqiiensis (Lawrence) 
which is from South Africa. The posterior pair of legs are rather 
long and the tibia is furnished with a large plume of long setae. The 
mites hold these legs, when running, either horizontally behind them 
or vertical, not using them for locomotion. The mite runs very rapidly 
and vibrates this last pair of legs. Several functions of this posterior 
pair of legs have been proposed by Lawrence 1937 — (a) an aid in 
locomotion, (b) sensory, (c) defence, (d) sexual. 

Rejerences: 

Ebeling, W. 1934. A new predaceous mite from southern California. Pan- 
Pacific Ent. 10(l):33-34. 

Grandjean, F. 1947. Etude sur les Smarididae et quelques autres Ery- 
throides (Acariens). Arch, de Zool. Expt. et Gen. 85(1):1-126. 

Lawrence, R. F. 1937. A new species of plume-footed mite from South 
Africa. Ann. South African Mus. 32(3) : 269-279. 

. 1940. New larval forms of South African mites from arthropod 

hosts. Ann. Natal Mus. 9(3) :401-408. 

Southcott, R. V. 1946. Studies on Australian Erythraeidae (Acarina). 
Proc. Linn. Soc. New South Wales 71 ( 1-2) :6-48. 

Smaridiidae Kramer, 1878 

Figures 178, 179 

Diagnosis: These mites have a longish, oval body which is pointed 
anteriorly and moderate shoulders. The propodosoma is usually drawn 
out into a long "nose" and a shallow furrow separates it from the 
hysterosoma. The dorsal surface of body is slightly convex and occa- 
sionally has several longitudinal and transverse depressions. Two sen- 
sillary areas, each with a pair of sensory setae, are located on the 
dorsum of the propodosoma. The crista metopica may be present or 
absent. One or two eyes are situated on each side of the propodosoma. 
The setae are of peculiar structure; they are usually in the shape of 
a leaf with thorns or hairs which are strongly curved and folded longi- 
tudinally. Coxae I and ii, and iii and iv are united, but the two groups 
are separated. The legs are slender, occasionally extremely long, and 
have six movable segments. Two claws are present on the tarsi but 



242 Acarology 

both pretarsus and empodium are lacking. The palpi have five segments 
with a thumb-claw complex. The chelicerae are long and stylet-like. 
The gnathosoma is capable of being projected far anteriorly or with- 
drawn into the body. No genital suckers are present. According to 
Grandjean there is no protonymph. Heteromorphic without urstigma 
the larvae possess trichoboths or sensory setae on the first pair of legs. 
The larvae also have a scutum which possesses two pairs of sensory 
setae and two pairs of ordinary setae. 





W<. /. * ^ 'J i A 



4;v.. ...... A /| 




L'^^ 



Figure 178 Smarts latreillei Grand- Figure 179 Smarts mamillatus (Say). 
jean. Larva. (After Grandjean 1947) Dorsum of female, gnathosoma par- 
tially extruded. 



Genera: 

1. Smarts Latreille, 1796 (= Smariidia Latreille, 1817 

lese, 1883) 
Type. Trombidium squamatum Hermann, 1 804 

2. Aecosmaris Grandjean, 1947 

Type. Aecosmaris calUtricha Grandjean, 1947 

3. Fessoniav. Heyden, 1826 

Type. Trombidium papillosa Hermann, 1804 

4. Hirstiosoma Womersley, 1934 

Type. Hirstiosoma scalaris Womersley, 1934 



Dugesia Ber- 



Trombidiformes 243 

5. Phanolophus Andre, 1927 

Type. Phanolophus nasica Andre, 1927 

6. Sclerosmaris Grandjean, 1947 

Type. Sclerosmaris philopempta Grandjean, 1947 

7. Sphaerotarsiis Womersley, 1936 

Type, Sphaerotarsiis allmani Womersley, 1936 

Southcott 1946 revised the family and divided it into four subfami- 
lies — the Smaridiinae, Fessoniinae, Hirstiosominae, and Phanoloph- 
inae. This system is not followed here. 

Discussion: This is a little known group of mites in which the larval 
forms are parasitic on insects and the adult forms are predaceous. 
Very few species are known, the best known fauna being that of Aus- 
tralia and Europe. The family is little known in North America, Ev/ing 
having described Hirstiosoma longilinealis (Ewing) from the Middle 
West, and Say another species from the East Coast — Smarts sericeum 
Say. 

Womersley and Southcott 1941 have studied the life history of a 
few of these mites and have been able to rear nymphs of Smarts prom- 
inens (Banks), an Australian species, from larvae found attached to 
psocids. They state, "when fully gorged the mites left their hosts and 
wandered freely about the tube for several days before becoming dor- 
mant. After several more days: the skin splits transversely, revealing 
the pupa. Three to four weeks later the nymph emerges from a rent 
towards the posterior end of the pupa. Whether a second resting stage 
and nymph occurs has not been ascertained, but seems to be unlikely." 
The presence of only one nymphal stage agrees with Grandjean's 
statement that the protonymph stage is lacking. Womersley and South- 
cott have also been able to correlate nymphs of Hirstiosoma and 
Sphaerotarsus with adults on morphological grounds, as Grandjean 
has been able to do with the larvae and adults found associated to- 
gether. 

References: 

Grandjean, F. 1947- Etude sur les Smaridiidae et quelques autres Ery- 

throides (Acariens). Arch, de Zool. Expt. et Gen. 85(1) : 1-126. 
Southcott, R. V. 1946. On the family Smaridiidae (Acarina). Proc. Linn. 

Soc. New South Wales 70(3-4) : 173-178. 
Womersley, H., and R. V. Southcott. 1941. Notes on the Smaridiidae 

(Acarina) of Australia and New Zealand. Trans. Roy. Soc. South 

Austral. 65(l):61-78. 



244 



Acarology 



Calyptostomidae Oudemans, 1923 

Figures 180,181 

Diagnosis: These are land-dwelling 
mites usually to be found in very wet 
places. Their body is square, plump, 
and truncate posteriorly with a dull 
or blunt point anteriorly. No suture 
separates the propodosoma and hys- 
terosoma. The dorsal body surface is 
flat with numerous depressions, lack- 
ing setae, which are places of muscle 
attachment. No crista metopica or 
area sensilligerae are present, but on 
the anterior portion of the propodo- 
soma there is a pair of pseudostigmata 
in the shape of a roundish cup from 
the bottom of which arise the short 
sensory setae. A pair of lenslike eyes 
are located on each side of the propo- 
dosoma. The dorsal setal bases are 
connected by sclerotized stripes in 
such a manner that the integument 
presents a design of stars, usually 
with a slender, leaf-shaped seta in the 
center of each star. The legs are 
slender, proportionately long, and have six movable segments. All 
tarsi lack pretarsus and empodium but have two claws. The palpi have 
five movable segments and the palpal tibia has a very short, weak tibial 
claw. The palpal tarsus is joined distally and directed anteriorly. The 

chelicerae are unsegmented, very long, 
and needle-like. The gnathosoma is 
highly projectile, and when in a state 
of rest it is retracted into the body. 
There are two pairs of genital suckers. 
The larvae are homomorphic, do not 

^'^'"Mf^u ^''^yP^^'^y ''["- have urstigma, and probably are para- 
rmw5 (Muller). Propodosomal . -. , , 

sensory setae. Sites of arthropods. 




Figure 180 Calyptostoma vehiti- 
niis (Miiller). Dorsum of female; 
legs not shown. 




Trombidiformes 



245 



Genus: 

Calyptostoma Cambridge, 1875 (= Smaris Berlese, 1887) 
Type. Acarus velutinus Miiller, 1778 (= Calyptostoma hardyi Cam- 
bridge, 1875) 

Discussion: A little-known group of predaceous mites. 



Trombidiidae Leach, 1815 

Figure 182 

Diagnosis: Nymphal and adult trombidiids can usually be recognized 
by their dense coat of setae that gives them a velvet-like appearance 
and by the division of their body into three more or less distinct sec- 
tions — gnathosoma, propodosoma, 
and hysterosoma. The body, how- 
ever, is never 8-shaped. The cheli- 
cerae consist of two segments, a 
basal muscular one and a curved, 
bladelike distal segment that is 
provided with sawlike teeth on its 





Figure 182 a Microtrombidiiim hys- Figure 182 h AUothrombium neapoli- 
tricinum (Canestrini). Dorsal view of tanum Oudemans. Dorsal view of 
adult. (After Vitzthum 1926) larva. (After Oudemans 1912) 



dorsal edge The stigmata open near the median, dorsal, proximal 
surface of the chelicerae and usually do not have free peritremes. 
The palps have five segments, and the palpal tarsus opposes a ter- 
minal tibial claw in thumblike fashion. The legs have six (exception- 
ally five) segments. A dorsal scutum or crista metopica is found on 
the median portion of the propodosoma. One (exceptionally two) 
pairs of sensillae are on the lateral expansions of the scutum. Anteri- 



246 Acarology 

orly the scutum ends in an expanded plate that may project over 
the gnathosoma as a tectum. This plate bears numerous setae, or 
the plate may be lacking and the scutum rudimentary, consisting of 
little more than areas for the origin of the sensillae. One subfamily 
(Stygothrombiinae) is extremely degenerate and lacks numerous 
setae, and typical mouth parts, and its body shape is long and worm- 
like. 

Larval trombidiids have a single urstigmen associated with leg i, 
usually more than one dorsal plate, and the seta on the pedipalpal 
coxa is usually anterior to the base of the palpal femur. These mites 
are parasitic on invertebrates. 

Thor and Willmann 1947 have divided the family into fifteen sub- 
families. One of these subfamilies, the Trombiculinae, is now recog- 
nized as a family and will be considered in the next section. A key to 
the subfamilies, based on adults, modified from Thor and Willmann, 
follows: 

Key to the Trombidiidae 

1. Propodosoma with crista enclosed in plates of various shapes or 
free in integument 2 

Propodosoma without crista; scutum rudimentary; sensillae at- 
tenuate and nude Trombellinae 

2. One pair of sensillae 4 
Two pairs of sensillae 3 

3. Three hysterosomal plates Notothrombiinae 
Hysterosomal plates lacking Johnstonianinae 

4. Sensillae arising from sensillary area 6 
Sensillae not arising from sensillary area 5 

5. Scutum expanded Calothrombiinae 
Scutum straight Tanaupodinae 

6. Peritreme associated with cheliceral stigmata; eyes on movable 
peduncles 7 

No peritreme present; eye if present not on movable peduncle 8 

7. Pulvillus present between ambulacral claws AUothrombiinae 
Pulvillus absent Trombidiinae 



Trombidiformes 247 

8. Sensillary area not anterior; two claws on legs 9 

Sensillary area in anterior region of scutum; three claws on legs 

Stygothrombiinae 

9. Sensillary area at the posterior end of scutum 10 
Sensillary area in mid region of scutum 1 1 

10. Single eye on either side of crista Tanaupodasterinae 
Double eye (exceptionally no eyes) on either side of crista 

Microtrombidiinae 

11. Setae nude 12 
Setae feathered 13 

12. Scutum with free anterior projection Rhinothrombiinae 
Scutum without free anterior projection Ocypetinae 

13. With dorsal pygidial plate Eutrombidiinae 
Without dorsal pygidial plate Holcotrombidiinae 

Trombidiinae Thor, 1935 
Genera: 

1. Trombidium Fabricius, 1775 (= Sericothrombium Berlese, 1910) 
Type. A cams holosericeus Linnaeus, 1758 

2. AustrothrombiumWomQrs\Qy,\9?>A 

Type. Allothrombium {Mesothrombium) australiense Hirst, 1929 

3. Caenothrombium Oudemans, 1927 

Type. Caenothrombium caloris Oudemans, 1927 

4. Dinothrombiiim Oudemans, 1910 
Type. Acarus tinctorius Linnaeus, 1767 

5. Phyllotrombidium Cooreman, 1946 
Type. Trombidium barbarum Lucas, 1846 

6. Xenothrombium Oudemans, 1927 

Type, Xenothrombium insulare Oudemans, 1927 

Allothrombiinae Thor, 1935 
Genera: 

1. Allothrombium Berlese, 1903 (= Mesothrombium Hirst, 1926) 
Type. Trombidium fuliginosum Hermann, 1804 

2. Corethrothrombium Oudemans, 1929 

Type. Corethrothrombium vandermeermohri Oudemans, 1929 



248 Acarology 

Calothiombiinae Thor and VVillmann, 1947 
Genus: 

Calothrombium Berlese, 1918 

Type. Parathromhium paolii Berlese, 1918 

Eutrombidiinae Thor, 1935 
Genera: 

1. Eutrombidiiim Verdun, 1909 

Type. Pediciilus rostratiis Scopoli, 1763 (= Trombidiiim trigoniim 
Hermann, 1804) 

2. Leptothrombium Berlese, 1912 

Type. Trombidiiim oblongiun Tragardh, 1904 

Johnstonianinae Thor, 1935 
Genera: 

1. Johnstoniana George, 1909 (= Rohaiiltia Oudemans, 1911) 
Type. Rhyncholophus errans Johnston, 1852 

2. Centrotrombidiiim Kramer, 1896 

Type. Centrotrombidium schneideri Kramer, 1896 

3. Diplothrombium Berlese, 1910 

Type. Trombidium longipalpe Berlese, 1887 

4. Hirstithrombiiim Oudemans, 1940 

Type. Diplothrombium australiense Hirst, 1928 

5. Myrmicotrombiiun Womersley, 1935 

Type. Myrmicotrombium brevicristatiim Womersley, 1935 

Microtrombidiinae Thor, 1935 

Genera: 

1. Microtrombidium Haller, 1882 (= Manriquia Boshell and Kerr, 

1942) 
Type. Trombidium purpureum Haller, 1882 

2. Anomalothrombium Andre, 1936 

Type. Anomalothrombium nasigeriim Andre, 1936 

3. Camerotrombidium Thor, 1936 
Type. Ottonia vesiculosa Thor, 1900 

4. Campy lothrombium Krausse, 1916 

Type. Microtrombidium langhofjeri Krausse, 1916 

5. Dendrotrombidium Thov, 1916 

Type. Trombidium perligerum Berlese, 1888 

6. Dromeothrombium Berlese, 1912 

Type. Trombidium macropodum Ber\QSQ, \903 



Trombidiformes 249 

1. Echinothrombiiini Womersley, 1937 
Type. Ottonia spinosa Canestrini, 1877 

8. Enemothrombiiim Berlese, 1910 

Type. 1 roinhiciiiim hifoliosuni Canestrini, 1884 

9. Eutrichothrombiiun Womersley, 1937 
Type, Jrombidium euthrichum Berlese, 1904 

10. Georgia WuW, 1918 

Type. Ottonia ramosa George, 1909 

11. Foliotrombidium Womersley. 1945 

Type. Enernothrombium evansi Womersley, 1937 

12. Hiotrombidium Womersley, 1945 

Type. Calothrombiuin tiibbi Womersley, 1937 

13. Eaminothrombium Womersley, 1937 

Type. Microtrombidium mynnicum Womersley, 1934 

14. Pedotrombidium Womersley, 1945 

Type. Pedotrombidium kohlsi Womersley, 1945 

15. Neotrombidmm Leonardi, 1901 

Type. Neotrombidmm iurcigerum Leonardi, 1901 

16. Platyseta Wharton, 1938 

Type. Platyseta yucatamcus Wharton, 1938 

17. Platytrombidium Thor. 1936 

Type. Trombidium vagabundum Berlese, 1903 

18. Spelaeothrombium Willmann, 1940 

Type. Spelaeothrombium caecum Willmann, 1940 

19. V algothrombium Willmann, 1940 
Type. Ottonia valga George, 1909 

Notothrombiinae Thor and Willmann, 1947 

Genus: 

Notothrombium Storkan, 1934 

Type. Notothrombium regis-borisi Storkan, 1934 

Otypetinae Vitzthum, 1941 

Genus: 

Ocypete Leach, 1814 ( = Podothrombium Berlese, 1910) 
Type. Ocypete rubra Leach, 1814 

Rhinothrombiinae Thor and Willmann, 1947 

Genus: 

Rhinothrombium Berlese, 1910 

Type. Trombidium nemoricola Berlese, 1886 



250 Acarology 

Holcotrombidiinae 

(new name for Scalothrombiinae Thor and Willmann, 1937) 
Genus: 

Holcotrombidium Womersley, 1945 {= Scalothrombium Thor and 

Willmann, 1947) 
Type. Euthrombium scalans Womersley, 1936 {Euthrombium is a 
lapsus for Eutrombidium) 

Stygothrombiinae Thor, 1935 
Genera. 

1. Stygothrombium Viets, 1932 

Type. Stygothrombium karamani Viets, 1932 

2. Cerberothrombium Viets, 1934 

Type. Stygothrombium {Cerberothrombium) armatum Viets, 1934 

Tanaupodasterinae Thor and Willmann, 1947 

Genus: 

Tanaupodaster Vitzthum, 1933 

Type. Tanaupodaster montezunia Vitzthum, 1933 

Tanaupodinae Thor, 1935 
Genera: 

1. Tanaupodus Haller, 1882 

Type. Tanaupodus steudeti Haller, 1882 

2. Eothrombmm Berlese, 1910 

Type. Eothrombmm echinatum Berlese, 1910 
3 Neotanaupodus Garman, 1925 

Type. Neotanaupodus tuberculatus Garman, 1925 

4. Tignyia Oudemans, 1937 

Type. Acarus sulcatus Miiller, 1776 

5. Typhlothrombium Berlese, 1910 

Type. Trombidium histricinum Leonardi, 1901 

Trombellinae Thor, 1935 
Genera: 

1. Trombella Berlese, 1887 

Type. Trombella glandulosa Berlese, 1887 

2. Chyzerm G. Canestrini, 1897 

Type. Chyzeria ornata G. Canestrini, 1 897 

3. Parachyzeria Hirst, 1926 { — Thaumatotrombium Andre, 1938) 
Type. Parachyzeria indica Hirst, 1926 



Trombidijormes 251 

Genera proposed for larvae whose subfamilial relationships are 
unknown. 

I A St I g ma ^vuy?ini, 1911 

Type. Astigma oudemansi Bruyant, 1911 

2. Atomus Latreille, 1795 

Type. Acarus parasiticus DeGeer, 1778 

3. Cercothrombium Methlagl, 1928 

Type. Cercothrombium loricatum Methlagl, 1928 

4. Ettmiilleria OudQm2iX\s, 1911 

Type. 1 rombidium sucidum Tragardh, 1910 

5. Heterotrombidium Verdun, 1910 

Type. Thrombidium granulatum Oudemans, 1902 

6. Hexathrombium Cooreman, 1944 

Type. Hexathrombium spatuhferum Cooreman, 1944 

7. Hoplothrombium Ewing, 1925 

Type. Hoplothrombium quinquescutatum Ewing, 1925 

8. Monunguis Wharton, 1938 

Type. Monunguis streblida Wharton, 1938 

9. Neothrombium Oudemans, 1909 

Type. Allotrombidium neglectum Bruyant, 1909 (Allotrombidmm is 
a lapsus for AUothrombium) 

10. Nothotromhicula Dumbleton, 1947 

Type. Nothotromhicula deinacridae Dumbleton, 1947 

11. Paratrombium Bruyant, 1910 

Type. Paratrombium egregium Bruyant, 1910 

12. PoM/^cfl Methlagl, 1928 

Type. Polydisca squamata Methlagl, 1928 

13. Womersleyia Radford, 1946 

Type. Womersleyia minuta Radford, 1946 

Discussion: The trombidiids are extremely numerous in both num- 
bers and kinds. Thor and Willmann include 304 species in their section 
on the family in "Das Tierreich." That this is only a fraction of the 
species that await description is proved by the fact that almost every 
collection of mites from litter will contain new species of trombidiids. 
The next family, the Trombiculidae, has been studied more extensively 
than the Trombidiidae. Thor and Willmann included these forms in 
their account of the Trombidiidae as the subfamily Trombiculinae. 
They listed 150 species of trombiculid, in addition to their 304 species 
ot trombidiids. Even with 150 species they failed to include all the 
new species discovered during World War 11. The total number of 
trombiculids is now about 300, and many parts of the world have not 



252 . Acarology 

yet been carefully surveyed for these mites. As a conservative estimate 
then, there are at least several thousand species of trombidiids, most 
of which await description. 

Trombidiids are world-wide in distribution and have been found 
on every major land mass except those covered by ice and snow the 
year around. They are more abundant in the tropics than in temperate 
climes and are a conspicuous portion of the mite faunas found on 
oceanic islands. 

The life history of trombidiid mites is as follows: egg, deutovum, 
larva, nymphochrysahs, nymph, imagochrysalis, imago. The life cycle 
of Eutrombidiiim rostratus has been well worked out by Severin 1944. 
Michener 1946 has found that microtrombidiids may undergo several 
postimaginal molts. The sex ratio is 1 : 1 in the cases investigated. The 
penis of the males will serve to distinguish them from females. 

Trombidiid larvae parasitize arthropods and because of this habit 
they may potentially be important not only in the control of arthropods 
but also in the transmission of micro-organisms from one arthropod 
to another. The nymphal and adult stages feed on the eggs and early 
larval instars of many arthropods, and thus aid in keeping down their 
numbers. Eutrombidiiim rostratus is an important enemy of the locust. 
Its larvae feed on the locusts and its adults feed on the eggs of locusts. 

References: 

Berlese, A. 1912. Tromb|diidae. Redia 8:1-291. 

Feider, Z. 1950. Cercetari asupra aparatului respirator la Trombidiidae 
si prostigmatele superioare si lista speciilor de Trombidiidae din Re- 
publica Populara Romana. Ann. Acad. Repub. Pop. Romane, Vol. 
3, mem. 5:1-185, Pis. 1-21. 

Michener, C. D. 1946. The taxonomy and bionomics of some Panamanian 
trombidiid mites (Acarina). Ann. Ent. Soc. Amer. 39:349-380. 

Severin, H. C. 1944. The grasshopper mite Eutrombidium trigoniun (Her- 
mann) an important enemy of grasshoppers. S. Dak. Agr. Expt. Sta. 
Tech. Bull. 3:1-36. 

Thor, S., and C. Willmann. 1947. Trombidiidae. Das Tierreich Lfg. 71b: 
187-541 + Pis. XXIX-XXXVI. 

Womersley, H. 1945. A revision of the Microtrombidiinae (Acarina, 
Trombidiidae) of Austraha and New Guinea. Rec. South Austral. 
Mus. 8:293-355. 



Trombidiformes 



253 



Trombiculidae Ewing, 1944 

Figures 183, 184 

Diagnosis: Nymphs and adults. They are about 1 mm. long and oval 
or more usually figure-8-shaped. The body is divided into three more 
or less distinct sections — gnathosoma, propodosoma, and hysterosoma. 
The cuticle is striated frequently with enlarged, platelike, setal bases. 
Eyes may be present or absent but if present are always located on 




muw 



Figure 183 Eiischongastia indica 
(Hirst). Dorsal view of nymph. (After 
Wharton 1946) 




Figure 184 Eiischongastia indica 
(Hirst). Dorsal view of larva. (After 
Wharton 1946) 



the propodosoma. The setae are filiform and densely pilose, covering the 
legs and body to give a velvety appearance. Made of five segments, the 
palps are well developed and a tibial claw is present. The palpal tarsus 
opposes the claw in a thumblike fashion. The chelicerae have a stout 
basal segment and a bladelike distal segment that bears a row of saw- 
like teeth on its dorsal edge. The legs have six segments, and each 
tarsus is provided with a pair of ambulacral claws. The genital opening 
is located between coxae iv. The males have a bladelike penis and 
numerous setae on the longitudinal genital valves, while the females 
have a similar opening but lack a penis and have few setae on the 
valves; the genital openings of both sexes have three pairs of genital 
suckers. The stigmata open on the basal segment of the chelicerae. A 
scutum is present with a posterior sensillary area that bears a pair of 
pseudostigmata from which arise elongated sensillae. The anterior end 
of the crista is expanded to form a tectum that bears one or two setae. 



254 Acarology 

Larvae. (The taxonomy of trombiculids is based primarily on the 
larvae.) The cheHcerae have two segments; the basal segment is stout 
and muscular while the distal segment is a sclerotized, curved blade 
with or without projections called teeth. The palps have five segments; 
the basal segments are fused along the midline and have a median, 
anterior, laminar projection that extends beyond the basal segment of 
the chelicerae and a pair of lateral wings or galeae that curl dorsal 
about the chelicerae and bear a seta on each side; each basal segment 
also bears a seta posterior to the junction with the palpal femur. The 
second palpal segment or femur bears a single seta; the third or genu 
bears a single seta; the fourth, or tibia, has three setae; one is dorsal, 
one lateral, one ventral, and there is a terminal palpal claw. The fifth, 
or tarsus, articulates ventrally with the tibia and opposes the palpal 
claw in thumblike fashion. It bears several setae (usually eight), the 
basal one of which is a striated sensory seta. The body is usually red 
but may be almost colorless; it bears a dorsal plate or scutum at the 
level of the anterior two pairs of legs, usually two pairs of eyes that 
flank the scutum, several rows of dorsal setae, several rows of ventral 
setae, occasionally a posterior plate or a posterior group of specialized 
setae, a ventral anus, three pairs of legs, an urstigma or sclerotized pit 
associated with the posterior distal angle of coxa i, and at times a pair 
of tracheal trunks that open through stigmata in the region of the 
gnathosoma. The scutum bears from three to six marginal scutal setae 
or infrequently more, and a pair of pseudostigmata from which the 
sensillae or pseudostigmatic organs arise. The legs are composed of 
six segments if the femur is undivided and of seven if the femur con- 
sists of a basifemur and telofemur. 

Wharton 1947 recognizes four subfamilies based on the larval 
morphology. 

Key to the Trombiculidae 

1. First pair of legs with seven segments 2 
All legs with six segments; two setae on coxa i Leeuwenhoekiinae 

2. Legs n and ni with seven segments 3 
Legs n and ni with six segments Walchiinae 

3. Paired, anterior, submedian, scutal setae and/or anteriormedian 

scutal projection Apoloniinae 

Not as above Trombiculinae 



Trombidiformes 255 



Leeuwenhoekiinae Womersley, 1944 

Genera and subgenera: 

1. Leeuwenhoekia OudiQ\r\?ins, \9\\ 

a. Leeuwenhoekia s.str. 

Type. H eterothrombidium verdiini Oudemans, 1910 

b. Comatacarus Ewing, 1942 

Type. Comatacarus americanus Ewing, 1942 

2. A comatacarus Ewing, 1942 

a. Acomatacarus s. str. 

Type. Acomatacarus arizonensis Ewing, 1942 

b. y^M^/racflrw^ Lawrence, 1949 

Type. Austracarus procaviae Lawrence, 1949 

c. Austrombicula Lawrence, 1949 

Type. Leeuwenhoekia womersley i Lawrence, 1949 

d. ^yracarM^ Lawrence, 1949 

Type. Hyracarus typicus Lawrence, 1949 

3. H anne mania Oud^mdiXxs, \9\\ 

Type. H eterothrombidium hylodeus Oudemans, 1910 

4. Odontacarus Ewing, 1929 

Type. Trombicula dentata Ewing, 1925 

5. Whartonia Ewing, 1944 

Type. Hannemania nudosetosa Wharton, 1938 

Walchiinae Ewing, 1946 
Genera: 

1. H^^/c/j/a Ewing, 1931 

Type. Trombidium glabrum Walch, 1927 

2. Gahrliepia Oudemans, 1912 

Type. Typhlothrombium nanus Oudemans, 1910 

3. Gateria Ewing, 1938 

Type. Gahrliepia fletcheri Gater, 1932 

4. Schongastiella Hirst, 1915 

Type. Schongastiella bengalensis Hirst, 1915 

Apoloniinae Wharton, 1947 

Genera: 

1. Apolonia Torres and Braga, 1938 

Type. Apolonia tigipioensis Torres and Braga, 1938 

2. Sauracarella Lawrence, 1949 (placement uncertain) 
Type. Sauracarella whartoni Lawrence, 1949 



256 Acarology 

3. W^om^n/fl Wharton, 1947 

Type. Womersia strandtnumiy^hdLVion, 1947 

Trombiculinae Ewing, 1929 

Genera and subgenera: 

1. Trombicida Berlese, 1905 

a. Trombicida s. str, (= Crotiscus Ewing, 1944) 

Type. Trombicula minor Berlese, 1905 (a collection of members 
of the genus Trombicida of uncertain affinities) 

b. Blankaartia Oudemans, 1911 (= Tragardhida Berlese, 1912 — 

PentagoneUa Thor, 1936 = Megatrombicida Michener, 1946) 
Type. Trombidium niloticum Tragardh, 1905 

c. Eutrombicula Ewing, 1938 (= Trombicidoides Jacot, 1938 and 

Acariscus Ewing, 1943) 
Type. Microthrombidium alfreddugesi Oudemans, 1910 

d. Fonsecia Radford, 1942 

Type. Trombicida ewingi Fonseca, 1932 

e. Leptotrombidium Nagayao et al., 1916 
Type. Trombidium akamushi Brumpt, 1910 

f. Neotrombicida Hirst, 1925 

Type. A earns autiimnalis Shaw, 1790 

g. Trombiculindus Radford, 1948 

Type. Trombiculindus squamosus Radford, 1948 

2. Ascoschongastia Ewing, 1946 

Type. Neoschongastia malayensis Gater, 1932 

3. Doloisia Oudemans, 1910 

Type. Doloisia synoti Oudemans, 1910 

4. Endotrombicula Ewing, 1931 

a. Endotrombicida s. str. 

Type. Endotrombicula penetrans Ewing, 1931 

b. Phrynacarus Lawrence, 1949 

Type. Phrynacarus fitzsimonsi Lawrence, 1949 

5. Euschongastia Ewing, 1938 

Type. Euschongastia americana Ewing, 1938 

6. Guntherana Womersley and Heaslip, 1943 
Type. Neoschongastia kallipygos Gunther, 1939 

7. Heaslipia Ewing, 1944 {— Trombicidoides Womersley and Heaslip, 

1943) 
Type. Trombicidoides gateri Womersley and Heaslip, 1943 

8. Myotrombicula Womersley and Heaslip, 1943 

Type. Myotrombicula vespertilionis Womersley and Heaslip, 1943 

9. Neoschongastia Ewing, 1929 (= Paraschongastia Womersley, 1939) 
Type, Schongastia americana Hirst, 1921 



Trombidiformes 257 

10. Novotrombicula Womersley and Kohls, 1947 

Type. Novotrombicula owiensis Womersley and Kohls, 1947 

11. Oenoschongastia Womersley and Kohls, 1947 

Type. Oenoschongastia cana Womersley and Kohls, 1947 

12. Riedlinia Oudemans, 1914 

Type. Riedlinia coeca Oudemans, 1914 

13. 5<7z/mci/5 Lawrence, 1949 

Type. Sauriscus ewingi Lawrence, 1949 

14. Schongastia Oudemans, 1910 

Type. Thrombidium vandersandei Oudemans, 1905 

15. Tecomatlana Hoffmann, 1941 

Type. Teconiatlana sandovali Hoffmann, 1947 

16. Trisetica Traub and Evans, 1950 

Type. Trisetica melvini Traub and Evans, 1950 

V nassigned genus: 

Speotrombicula Ewing, 1946 

Type. Trombicula trifurca Ewing, 1933 (based on an adult) 

Discussion: Trombiculids are very similar in their behavior to trom- 
bidiids. As nymphs and adults they feed on eggs and early larval in- 
stars of small arthropods. The stages in their life history are the same 
as those of trombidiids, with the exception that no trombiculid is known 
to undergo postimaginal molts. The big difference in their behavior is 
the host preference of the larvae. Trombiculids, with few exceptions, 
e.g. Acomatacarus paradoxa Andre, parasitize terrestrial vertebrates 
including man and his domestic animals. 

Larvae (chiggers or red-bugs) belonging to the genera Trombicula 
and Schongastia are insufferable human pests in many parts of the 
world. In the United States, T. (E.) alfreddugesi (Oudemans), T. 
(E.) splendens Ewing, and T. (E.) batatas (Linnaeus) are responsi- 
ble for an irritating dermatitis. Some individuals are immune from the 
effects of these chigger bites, while others will develop a blister meas- 
uring several inches across at the site of a bite. 

In the Orient, species of Trombicula (Leptotrombidium) are the 
vectors of a rickettsial disease known as scrub typhus or tsutsugamushi 
disease. This disease caused a total of over 7,000 casualties in the 
United States armed forces during World War II. No estimates are 
available as to how prevalent the disease is in natives of many areas. 

Trombiculids are not only pests and vectors of disease from one 
animal to another but are also damaging parasites of economically 



258 Acarology 

important birds and animals. In Australia Trombicula (Emrombicuui) 
sarcina is an important pest of sheep. Apolonia tigipioensis deplumes 
chickens. Species of Neoschongastia are also harmful to poultry, as 
are the common pest chiggers. 

Trombiculids are as well known as any of the other mites and yet 
the 300 or more described species probably do not represent more 
than half the species that will eventually be known. 

References: 

Berlese, A. 1912. Trombidiidae. Redia 8:1-291. 

Ewing, H. E. 1944. The trombiculid mites (chigger mites) and their rela- 
tion to disease. J, Parasitol. 30:339-365. 

Lawrence, R. F. 1949. The larval trombiculid mites of South African ver- 
tebrates. Ann. Natal Mus. 11:405-486. 

Philip, C. B. 1948. Tsutsugamushi disease (scrub typhus) in World War 
II. J. Parasitol. 34:169-191. 

Thor, S., and C. Willmann. 1947. Trombidiidae. Das Tierreich Lfg. 71b: 
187-541 + Pis. XXIX-XXXVI. 

Wharton, G. W. 1947. Studies on North American chiggers II. The sub- 
families and Womersia strandtmani, n. gn., n. sp. J. Parasitol. 33: 
380-384. 

, D. W. Jenkins, J. M. Brennan, H. S. Fuller, G. M. Kohls, 

and C. B. Philip. 1951. The terminology and classification of trom- 
biculid mites (Acarina: Trombiculidae). J. Parasitol. 37(1): 13-31. 



CHAPTER VI 



Hydrachnellae Latreille, 1802 

(Hyclracarina) 



THE water mites form an ecological rather than a morphological 
group. Some are swimming, while others are nonswimming. They 
are inhabitants of fresh water except for the marine Pontarachnidae. 
The marine Halacaridae, although closely allied to the Cunaxidae, are 
also included here because of the habitat. The Hydrachnellae have 
cuticular glands, stigmata and tracheae (with the exception of the 
Pontarachnidae). Two pairs of eyes are present and may be either 
separate or coalesced; an imperfectly developed median eye is also 
pjresent at times. The tarsi usually possess two claws but are without 
empodium or pretarsus. The palpi usually have five movable segments.. 
The chelicerae have only the movable digit which is usually sickle- 
shaped. The larvae, with the exception of Hydrovolziidae and Hal- 
acaridae, are heteromorphous and have urstigma between coxae i 
and II. 

The information on this group is taken from the works of Lundblad, 
Viets, and Vitzthum. Although the European species are well known, 
little has been done in this country except by Wolcott and later by 
Marshall. However, neither of them has published comprehensive 
works which will give the student an over-all grasp of the subject. 
Little is known about the biology of 'the group as a whole, although 
a few common species have been studied. Some work has been done 
on the immature stages but here, as in many other groups, much rear- 
ing work is needed. 

The brightly colored watermites are to be found in lakes or ponds, 
along shores and in streams. A few are parasitic in the gills of fresh- 
water mussels, and the larvae of other forms are parasitic on aquatic 
insects much as chiggers are on vertebrates. Adult forms are preda- 

259 



s 



260 Acarology 

ceous and feed on Crustacea, insect larvae, and other water animals 
which are small enough to be captured. Some watermites are also para- 
sitic in all stages in the gill chambers of crabs and are adapted for 
grasping the gill filaments. They are to be found at all times of the 
year but usually most of the species appear as adults in late summer 
and fall. 

The Halacaridae, although closely related to the Cunaxidae, are 
treated here with the true watermites because of the similarity of habi- 
^ tat and the relative ease of identifying them by their habits. 
^_ Keys (from Viets 1936) to the superfamilies and families are given. 
Those who are interested in keys to the numerous subfamilies are re- 
ferred to Viets. 

References: 

Only a few references are given. No attempt is made to make the list 
comprehensive, since this is one of the most extensively worked groups and 
a complete list is beyond the scope of this work. However, in the few 
papers cited it is hoped that the reader can find the necessary leads to 
understand the group better. 

Lundblad, O. 1927. Die Hydracarinen Schwedens. I. Zool. Bidr. Uppsala 

11:185-535. 
. 1931. Sudamerikanische Hydracarinen. Zool. Bidr. Uppsala 13:1- 

86. 
. 1941. Eine Ubersicht des Hydrachnellensystems und der bis jetzt 

bekannten Verbreitung der Gattungen dieser Gruppe. Zool. Bidr. 

Uppsala 20:359-379. 
. 1941. Die Hydracarinenfauna SUdbrasiliens und Paraguays. Kungl. 

Svenska Vetenskapsakademiens Handlinger, Ser. 3, 19(7) : 1-183. 

. 1942. Ibid. 20(2):1-175; 20(8):1-171. 

Marshall, R. The complete works are needed for the study of the United 

States fauna; not comprehensive in nature. 
Viets, K. 1936. Wassermilben oder Hydracarina (Hydrachnellae und Hal- 
acaridae). Die Tierwelt Deutschlands 31:1-288; 32:289-574. 
Wolcott, R. H. 1918. The Water Mites (Hydracarina). Chapter XXVI, 

pp. 851-875. In Ward and Whipple's Fresh Water Biology, John 

Wiley and Sons, Inc. 

Key to the Hydrachnellae Superfamilies ' 

1. Without genital suckers; red, nonswimming, living in the upper 
courses of brooks Hydrovolziae 

With genital suckers (except marine forms) 2 

1 From Viets 1936. 



Hydrachnellae 261 

2. With narrow subulate rostrum; chelicerae on the whole dagger- 
like, without distinct separation between the claw and basal seg- 
ment (fresh water forms) Hydrachnae 

Without narrow subulate rostrum; chelicerae not dagger-like, with 
claws and basal segments distinctly separated from one another 
(except marine forms) 3 

3. Genital suckers often very small, not lying on the plates or lobes, 
nor under them, but free in the skin (then usually minute), or 
more or less enclosed by sclerotic clasps (then frequently stalked 
and acorn-shaped) ; eyes in eye capsules Limnocharae 

Genital suckers usually distinct, lying on or under the lobes or on 
the plates or connected to sucker areas in the ventral armor (ex- 
cept certain Fiona spp. with scattered discoidal suckers lying in 
the ventral skin) 4 

4. Genital organ with movable valves or lobes 5 
Genital organ without movable valves or lobes 6 

5. Genital suckers more or less knobbed, lying on lobes or united 
with them, isolated when lying free Hydryphantae 

Genital suckers under or beside inner margin of lobes in region of 
genital opening, not sclerotically united with lobes Lebertiae 

6. Palpi without apical claw between more or less spiniform palpal 
segment v and distal end of broadened segment iv 7 

Palpi with apical claw between palpal segment iv (whose distal 
margin more or less broadened and whose distal corner on the 
curved side more or less drawn out forwards) and clawlike seg- 
ment V Arrhenurae 

7. Genital organ with more or less distinct sucker plates and with 
disklike or porelike suckers lying on them 8 
Genital organ with swelling similar to lobes but firmly fused with 
ventral armor; suckers, which are few, in region of genital opening 
(except in Midea with sucker plates; palpal segment iv subulate 
and reduced) Mideopsae 

8. Bodies generally with soft skin, rarely with more or less extensive 
dorsal plates or still more rarely completely armored; palpal seg- 
ment IV generally with frequently minute sclerotic process on 
curved side at distal median corner Pionae 
Body always armored, with narrow dorsal arch; palpal segment 

IV without sclerotic process on curved side at distal median corner 

Axonopsae 



262 



Acarology 



List of superfamilies and families: 

Hydrovolziae 

Hydrovolziidae Thor, 1905 

Hydrachnae 

Hydrachnidae Leach, 1815 

Limnocharae 

Limnocharidae Kramer, 1877 
Eylaidae Leach, 1815 
Protziidae Viets, 1926 

Hydryphantae 

Hydryphantidae Thor, 1900 
Clathrosperchonidae Lundblad, 

1936 
Ctenothyasidae Lundblad, 1936 
Eupatrellidae Viets, 1935 
Hydrodromidae Viets, 1936 
Rhynchohydracaridae Lundblad, 

1931 
Thermacaridae Sokolow, 1927 

Lebertiae 

Lebertiidae Thor, 1900 
Anisitsiellidae Viets, 1929 
Atractideidae Thor, 1 902 
Mamersopsidae Lundblad, 1930 
Pseudohydryphantidae Viets, 
1926 



Rutripalpidae Sokolow, 1934 
Sperchonidae Thor, 1900 
Teutoniidae Lundblad, 1927 

Arrhenurae Oudemans, 1902 
Arrenuridae Thor, 1900 

Mideopsae 

Mideopsidae Thor, 1928 
Acalyptonotidae Thor, 1929 
A-Thienemanniidae Lundblad, 

1930 
Krendowskiidae Lundblad, 1930 
Mideidae Viets, 1929 

Pionae Viets, 1930 
Pionidae Thor, 1900 
Astacocrotonidae Thor, 1927 
Feltriidae Thor, 1929 
Hygrobatidae Koch, 1 842 
Limnesiidae Thor, 1900 
Nautarachnidae Viets, 1935 
Neotorrenticolidae Lundblad, 

1936 
Pontarachnidae Thor, 1929 
Unionicolidae Oudemans, 1909 

Axonopsae 

Axonopsidae Viets, 1929 



S 



2. 



Key to the Hydrachnellae i 

Body strongly armored with several plates; genital suckers not 
present; anal opening lying in plate of intermediate or large size 2 

Body may or may not be strongly armored but not as above; with 
genital suckers (exception: Pontarachnidae); anal opening almost 
without exception not lying in large plate; legs (except in Oxinae) 
more or less radial 3 

Body strongly armored with several plates; three pairs of genital 
suckers present; genital and anal openings in same ventral plate; 
legs I and ii point anteriorly; legs iii and iv point posteriorly; no 
swimming hairs; found in ocean Halacaridae 

Legs III and iv attached laterally so that epimera project beyond 
edge of body and can be seen from above; epimera separated by 
From Viets 1936. 



Hydrachnellae 263 

well-defined sutures; anal opening in large plate; epimera i not 
forming tube Hydrovolziidae 

Legs II and iv arranged so epimera not seen from above; epimera 
not separated by suture; anal opening in small plate; epimera i 
closes together anteriorly to form tube Rhynchohydracaridae 

3. Rostrum not elongate or awl-like, but conelike or other form and 
essentially shorter than palpus; chelicerae definitely two-segmented 
and with sickle-like cheliceral claw and basal segment 4 
Rostrum long, narrow, awl-like, more or less pointing ventrally 
and reaching about to tip of palpus; chelicerae, on the whole, 
slightly curved and stylet-like, the cheliceral claw and basal seg- 
ment not noticeably separated; chelicerae with posterior end reach- 
ing far into interior of body Hydrachnidae 

4. Genital organ without valvelike flaps or plates but with ledgelike 
or clasplike sclerotic structure surrounding genital suckers; genital 
suckers fastened in soft body skin, very small or more or less 
stalked and posteriorly often acorn-like 5 
Genital organs with valvelike or platelike sclerotic sections, on or 
under which are more or less distinct genital suckers (exception: 

a Fiona species with dispersed, disklike suckers on ventral skin) 7 

5. Double eyes either located medianly on ends of transverse scle- 
rotic shield to form so-called spectacle or lie laterally either in 
shields or free in skin; palpi of normal size and much longer than 
rostrum 6 
Double eyes located laterally on more or less rodlike longitudinal 
sclerotic shield; palpi very small, only weakly surpassing rostrum; 

all legs richly haired but without true swimming hairs; body so 
soft that mite collapses when removed from water Limnocharidae 

6. Double eyes lie medianly and are bound together by single trans- 
verse plates, or are lateral and are bound together by many-seg- 
mented plate; no true rostrum present but with large sucking 
mouth surrounded by "ruffles"; palpal segment iii with group of 
setae on distal end; in the mites with-^eyes bound together by trans- 
verse plate genital suckers tiny and distributed over entire body 
skin; whereas in other group suckers are large and lie in shields on 
each side of genital opening Eylaidae 
Double eyes lie laterally, free in the body skin, without sclerotic 
plate connecting them; rostrum present; mouth opening not 
sucker-like and without "ruffles"; no group of setae on distal end 

of palpal segment in; genital suckers often stalked and acorn-like 

Protziidae 



264 Acarology 

7. Genital organs possess more or less arched and movable genital 
plate which through its movement opens the genital lips 8 

Genital organs without movable plates 19 

8. Many genital suckers, either small and porelike, or a few large, 
button-like ones on genital plates or connected with these plates; 
suckers isolated, occurring free between plates in genital lip re- 
gion; palpal segment iv with or without clawlike or finger-like 
projection on distal end which forms short pincers with palpal 
segment v; frontal organ usually present; claws of legs usually 
simple, sickle-like, and without empodium 9 

Genital suckers, usually three on each side and seldom two, four, 
six or more, lie in a row, one after other, under or near inner edge 
of genital plates but not connected with plates; palpal segment iv 
without distal projection which forms shear with segment v; 
frontal organ lacking, with few exceptions; tarsal claws often 
double-pronged and with empodium 12 

9. Palpal segment iv usually with robust spine or conelike appendage 
on distal end which is not equal in length to palpal segment v and 
does not form pincer; paired lateral eyes rarely found close to- 
gether in sclerotic plate 10 

Palpal segment iv with narrow, finger-like projection on its distal 
end which opposes ultimate segment and forms shear with it; lat- 
eral eyes not in capsules, separated from each other; frontal organ 
not present; body skin weak and without sclerotic plates 

Hydrodromidae 

10. Legs without true swimming hairs 1 1 
Legs with swimming hairs; body usually soft-skinned and usually 
with sclerotic plate on anterior portion; seldom many plates 

Hydryphantidae 

11. Body covered with beautifully designed radiating sclerotic plates; 

with many genital suckers Clathrosperchonidae 

Body simply armored; with many genital suckers; living in hot 
springs Thermacaridae 

Body without armor but with skin papillae; with three pairs of 
large genital suckers Ctenothyasidae 

12. Palpal segments iv and v not dorso-ventrally flat and shovel-like 13 

Palpal segments iv and v medio-laterally broadened and dorso- 
ventrally strongly flattened, and with four medio-laterally end 
claws of segment v forming shovel-like organ Rutripalpidae 



Hydrachnellae 265 

13. Palpi in general narrow; palpal segment ii seldom clublike, not 
longer than segment iv; segment iv as long or usually longer than 
segment ii; dorsal length of palpal segment ii never equals seg- 
ments III plus IV, but III plus IV longer than segment ii 14 

Palpi short and clublike; palpal segment ii especially thick and 
strong; palpal segment iv shorter than segment ii; dorsal length 
of segment ii same or longer than segments in plus iv; cheliceral 
claw proportionately small Mamersopsidae 

14. Palpal segment iv without sclerotic process on inner side; segment 
II usually with pegs or spines on inner side; skin without thick, 
spiny sclerotic plates 1 5 

Palpal segment iv dorsally-distally elongated; segment ii without 
appendage, peg, or spine on inner side; skin densely covered with 
thick-shafted, many-pointed, spiny sclerotic plates 

Pseudohydryphantidae 

15. Epimera in four groups of two each; these groups (at least second 
and third) separated from one another by skin areas 16 

Epimera united into one group, often medianly united with one 
another; laterally epimera ii and iii completely united without 
suture or only partial suture present; genital plates fit snugly into 
epimera iv without free ventral skin being present 18 

16. No gland on epimera iv 17 
Large, glandular organ on anterior median corner of epimera iv 

Teutoniidae 

17. Lateral eyes united in eye capsules; palpal segment ii with spine- 
covered projection on inner side; legs iv with claws Sperchonidae 

Lateral eyes not united in capsules but separated from each other 
by skin; palpal segment ii only with spines on inner margin; legs 
IV without claws Anisitsiellidae 

18. Epimeral region not fused with ventral region and genital organ 
therefore not enclosed; ventral region behind genital organ unar- 
mored and membranous; dorsum as a rule not sclerotized; dorsal- 
ventral suture lacking; with six (seldom four) large genital suckers 

Lebertiidae 

Epimeral region forming with venter (including genital organ) 
ventral armor which is closed behind genital organ; this extends 
laterally around body to dorsum where it is separated from dorsal 
shield by dorsal suture; genital organ with twelve small genital 
suckers under inner margin of genital flaps Atractideidae 



266 Acarology 

19. Genital suckers present; fresh-water mites 20 

Genital suckers not present: marine mites, on littoral of seas 

Pontarachnidae 

20. No shears formed by palpal segments iv and v 21 

Clawlike palpal segment v so hinged to dorsal distal portion of 
segment iv that two segments form pincers; two fine sensory or 
grasping setae on inner margin of segment v; segment v usually 
with strong spine; body armored 30 

21. Lateral eyes united (Astacocrotonidae with pair of eyes); leg iv 

as a rule with claws 22 

Lateral eyes separated from each other; leg iv usually without 
claw; palpal segment ii often with sclerotic cone on inner edge; 
with three pairs of genital suckers Limnesiidae 

As above but with many genital suckers Neotorrenticolidae 

22. Body as a rule membranous; seldom with more or less extensive 
dorsal plates; very seldom with completely hardened ventral and 
dorsal shields; epimera usually in four groups; sutures between 
them usually present but in several cases median suture between 
first epimera disappears or suture between third and fourth pair 
of plates not fully developed; genital organ of cutaneous or mem- 
branous form with distinct plates containing the more or less disk- 
like, seldom porelike, suckers; palpal segments ii, in, and iv fre- 
quently with cones or tubercles on inner margin 23 

Body almost entirely armored, dorsal and ventral armor generally 
separated by narrow dorsal suture; in a few cases genital organ 
in membranous area, or only ventral armor present; body usually 
flat, often discoidal; epimeral sutures lacking; genital organ be- 
tween epimeral region and posterior end of body; the six, eight 
or more genital suckers lie upon more or less distinct plates, and 
ledgelike or roundish plates often united with ventral shield; if 
genital organ lies in vicinity of epimeral region then orifice usually 
in opening of ventral shield, and genital suckers lie on valvelike 
plates, or under or at inner edge of flaplike genital "rolls" which 
unite with ventral shield; the medial distal edge of palpal seg- 
ment IV without sclerotic projection 27 

23. Epimera i separated from one another behind rostral base by su- 
ture or skin area; rostrum, as a rule, lies free and is not united with 
epimeral region; legs generally have swimming hairs; palpal seg- 
ment II without pegs or cones on inner margin (exception: Pseu- 



Hydrachnellae 267 

dofeltria) ; palpal segment iv with many teeth or hair tubercles on 
inner margin 24 

Epimera i usually united with one another and without median 
suture; posterior margin of rostrum frequently united with epi- 
mera i; legs without swimming hairs; genital organ usually with six 
suckers, in rare cases more, but not over twenty suckers on each 
side; genital suckers distinctly disklike; palpal segment ii with peg 
or sclerotic tooth on inner side; palpal segment iv without inner 
tooth but perhaps with small tubercle bearing setae Hygrobatidae 

24. Without narrow rostrum, at best with short mouth cone 25 

With narrow rostrum about one-third length of organ; genital 
plates possess many small, porelike suckers; legs with swimming 
hairs Nautarachnidae 

25. Usually found in stagnant waters and also in slow-moving water 
but seldom in cold streams; body usually weak-skinned, smooth, 
and seldom more or less entirely armored; palpal segment iv with 
conelike protuberance on inner margin; genital suckers usually 
disklike and distinct, seldom small and porelike; legs usually with 
swimming hairs; leg in of male without processes 26 

Small mites usually living in streams; with flat body, dorsum with 
more or less extensive plate which covers anterior and median 
dorsal region and which is surrounded by small, paired plates in 
striated region; palpal segment iv without conelike projection on 
inner margin; epimera iv with large, linear expansion on lateral 
margin; legs without swimming hairs; leg in of male usually with 
processes; genital organ of male has many small, porelike suckers 
on large, medianly united plate and has small genital opening; 
genital opening of female large, lying between two genital plates 
and often cleftlike, extending around terminal part of body 

Feltriidae 

26. Body without plates; distal palpal segment with stout spines, some 
hooklike, for grasping gills of crab- on which it is parasitic; no 
swimming hairs on legs; large gland on coxa iv; coxae arranged 
in two groups, lateral groups contiguous; four pairs of genital 
suckers on plates; genital opening on rear, far from epimeral re- 
gion; no eyes in female; pair of eyes in immature male 

Astacocrotonidae 

Gland pores of skin often conelike, raised; basal segments of 
chelicerae usually united medianly with one another; palpal seg- 
ment III often with very long, lateral spine; posterior part of epi- 



268 Acarology 

mera i and ii often with common, rodlike, long process which 
often reaches subcutaneously far under epimera in or even under 
iv; posterior margin of epimera iv usually transverse and as a rule 
without or only insignificant central process, and therefore with- 
out concave, medial region or genital indentation between coxae 
or epimera; genital organ usually back of epimeral region; legs i 
and II frequently thickened in proximal and middle segments and 
covered with paired, swordlike setae; tarsal claws as a rule simple, 
sickle-like, and without processes; legs iv of male not usually sexu- 
ally differentiated Unionicolidae 

Gland pores of skin not conelike; chelicerae separated from each 
other; palpal segment in without lateral spines; posterior process 
of anterior epimera short, with hooklike tips, and as a rule not 
reaching beneath posterior epimera; posterior end of epimera iv 
with median process, forming genital indentation; genital organ 
usually close to epimera and removed from posterior margin of 
body; legs i and ii without conspicuous setae and not thickened; 
tarsal claws usually forked and with processes; legs in and iv of 
male usually sexually differentiated Pionidae 

27. Genital suckers lie on more oi less sickle-like plates in deep geni- 
tal indentation, or the six, eight, or more suckers lie in "lipfields" 
(exception: $ of Momonia in which suckers are on flaplike plates 
in partially armored ventral skin) beside or under inner edge of 
genital rolls which are united with ventral plate; genital organ 
close to epimera iv, often in deep genital indentation; body in lat- 
eral view very round; palpal segment ii without protuberances on 
inner margin; segment iv often with processes on inner margin 28 

Six, eight, or more genital suckers on more or less distinct, round- 
ish, or ledgelike plate; plates on rear of body, more or less free in 
male, united with ventral plates; true genital indentation present; 
body, more or less flat, as a rule distinctly longer than broad; epi- 
mera often united medianly with one another; palpal segment ii 
at times with protuberance on inner margin; segment iv with tiny 
inner setae Axonopsidae 

28. Palpal segment iv shorter than segments ii plus in; genital inden- 
tation does not reach to epimera i and is either formed by mar- 
gins of posterior epimeral plates or is entirely lacking; genital 
suckers lie in "lipfields" at inner margin of flaplike but solid, im- 
movable genital folds which limit laterally genital opening in ven- 
tral armor (exception: 9 of Momonia in which folds are narrow 
and not united with ventral shield) ; body usually disklike and 
flat 29 



Hydrachnellae 269 

Palpal segment iv long, awl-like and longer than segments ii plus 
III; genital organ almost completely within deep genital indenta- 
tion which reaches to posterior end of united epimera i; numerous 
genital suckers on plates; body armored and highly arched; dorsal 
suture separates dorsal and ventral shields Mideidae 

29. Body entirely armored; dorsal shield separated from ventral shield 
by suture; inner margin of palpal segment iv does not surpass 
proximal end of palpal segment v; segment iv not dorso-ventrally 
broadened or thickened; genital organ with six to ten suckers; 
epimera as a rule separated by suture in median line Mideopsidae 

Body unarmored dorsally and without dorsal suture; palpal seg- 
ment IV dorso-ventrally thickened distally; inner side of palpal 
segment iv surpasses proximal end of segment v and forms shear- 
like organ; genital organ with many suckers; epimera without 
median suture; posterior group medianly joined at angle 

Acalyptonotidae 

30. Four, six, eight or more usually disklike genital suckers are, as a 
rule, in "lipfields" which lie in opening in ventral shield near inner 
edge of the more or less valvelike, arched, but immovable genital 
"rolls" 31 

Only genital lips, not many porelike genital suckers, lie in opening 
of ventral shield; genital suckers do not lie in opening of ventral 
armor but next to opening on more or less distinct, generally 
winglike plates in ventral armor; genital suckers usually numer- 
ous, small, and porelike; male often with appendage or petiole on 
rear of body Arrenuridae 

31. Many small genital suckers A-Thienemanniidae 

Three to eight pairs of large genital suckers arranged in longitudi- 
nal row Krendowskiidae 

The paper on the family Stygomonidae Szalay, 1943, type Stygo- 
monia latipes Szalay, 1943, has not been seen at this date. 



Halacaridae Murray, 1876 ^ 

Figures 185, 186 

Diagnosis: The halacarids are trombidoidea with a body typically 
flattened or, more rarely, circular in cross section and elliptical in out- 
line. The mouthparts form a distinct capitulum which nearly always 

1 From Newell 1947. 



270 



Acarology 



projects well beyond the anterior margin of the body but in a few 
forms is completely hidden in the dorsal view The palpi have three 
or four segments which are attached laterally, dorso-laterally. or dor- 
sally to the base of the capitulum. The maxillary portions of the palpi 
are completely fused. Lying in a dorsal groove in the rostrum the che- 
licerae are retractile; the ventral digit is large and movable while the 
dorsal digit is reduced to a pointed membrane. The tracheal system is 
very rudimentary and quite certainly is not functional in respiration. 






Figure 185 Halacarus {Thalassarach- 
na) subterraneus (Schuiz). Dorsum of 
male. (After Newell 1947) 



Figure 186 Copidognathus {Arhodeo- 
poms) siibmarinus Newell (left), pal- 
pus of female; Halacarus {Thalas- 
sarachna) cap/yzmw^ Lohmann (right), 
chelicera of female. (After Newell 
1947) 



Usually four plates dorsally (predorsal, postdorsal, and right and left 
ocular plates) and four plates ventrally and laterally (anterior epimeral, 
right and left posterior epimeral, genito-anal plates) reinforce the cuti- 
cle of the body wall. These plates show varying degrees of subdivisions 
or fusion in different genera, in different species of a single genus, or 
rarely in the two sexes of a single species. The legs are attached later- 
ally: legs I and ii are borne on anterior epimeral plate (or plates), and 
project anteriorly; legs in and iv are borne on the right and left pos- 
terior epimeral plates and project posteriorly. In adults the legs have 
six segments. The larvae have only three pairs of five-segmented legs. 
Leg IV in the protonymph is also five-segmented but legs i, ii, and iii 
are six-segmented. All legs in the deutonymph are six-segmented. The 
tarsus always has two lateral claws while a median claw may be pres- 
ent or absent. The salivary glands are well developed. The mid-gut does 



Hydrachnellae 271 

not open by way of the anus. The anus is present, but functions en- 
tirely as an opening for the single, dorsomedian, excretory tubule. The 
sexes are separate; sexual dimorphism is marked in the genito-anal 
plate and genitaha; other structures are usually (but not always) iden- 
tical in form in both sexes. Three eye spots are apparently always 
present, the corneas number two, four, or six or may be absent. The 
median eye has no cornea. There are three pairs of genital suckers. 
These mites are principally marine, but there are numerous fresh- 
water forms ("Porohalacaridae" of Viets). They are not capable of 
swimming and are predominantly predaceous or herbivorous, although 
three parasitic genera are known. Newell 1947 gives keys to the sub- 
families. 

Rhombognathinae Viets, 1927 ) 

Genera: 

1. Rhombognathides Viets, 1927 
Type. Aletes pascens Lohmann, 1889 

2. Isobactrus Newell, 1947 

Type. Aletes setosus Lohmann, 1889 

3. Metarhombognathus Newell, 1947 

Type. Rhombognathus annatus Lohmann, 1893 

4. Rhombognathus Trouessart, 1888 
Type. Pachygnathus notops Gosse, 1855 



Actacarinae Viets, 1939 
Genus: 

Actacarus Schulz, 1936 

Type. Actacarus pygmaeus Schulz, 1936 

Halacarinae Viets, 1927 
Genera: 

1. H alacar us Go?,SQ, \^55 

a. Halacarus s. str. 

Type. Halacarus ctenopus Gosse, 1855 

b. Thalassarachna Packard, 1871 
Type. Acarus basteri Johnston, 1836 

2. Agaue Lohmann, 1889 

Type. Halacarus parvus Chilton, 1883 

3. Agauopsis Viets, 1927 

Type. Agaue brevipalpus Trouessart, 1889 

4. Co/o^oc^-ra^ Trouessart, 1889 

Type. Coloboceras longiusculus Trouessart, 1889 



lO-J 



^3) 



272 Acarology 

5. Copidognathus TrouessarX, ISSS 

a. Copidognathus s. str. (= Copidognathopsis Viets, 1927 

= Werthella Lohmann, 1907) 
Type. Copidognathus glyptoderma Trouessart, 1888 

b. Arhodeoponis Newell, 1947 

Type. Copidognathus {Arhodeoporus) arenarius Nev^oil, 1947 

6. Po/7/flc«rM5 Lohmann, 1901 

Type. Halacams basidentatus Trouessart, 1900 

Porohalacarinae Viets, 1933 
Genera: 

1. Porohalacarus Thor, \92h 

Type. Halacarus alpinus Thor, 1910 

2. Caspihalacarus Viets, 1928 

Type. Caspihalacarus hyrcanus Viets, 1928 

3. Lohohalacarus Viets, 1939 (= Walterella Romijn, 1924 nom. 

praeocc. ) 
Type. Walterella weberi Romijn, 1924 

4. Troglohalacarus Viets, 1937 

Type. Troglohalacarus dentipes Viets, 1937 

Lohmannellinae Viets, 1927 
Genera: 

1. Lo/7/nfl/7/7e//a Trouessart, 1901 

Type. Leptognathus falcatus Hodge, 1863 

2. Porolohmannella Viets, 1933 

Type. Leptognathus violaceus Kramer, 1879 

3. Scaptognathus Trouessart, 1889 

Type. Scaptognathus tridens Trouessart, 1889 

Simognathinae Viets, 1927 
Genera: 

1. Simognathus TvouQSSSivU 1889 

Type. Pachygnathus sculptus Brady, 1875 

2. Acaromantis TYOXXtssdiYi and Neumann, 1893 

Type. Acaromantis squilla Trouessart and Neumann, 1893 

3. A telopsalis TrouesssiTt, 1S96 

Type. Atelopsalis tricuspis Trouessart, 1896 

4. IschyrognathusJrouQS^diVi, 1900 

Type. Simognathus coutieri Trouessart, 1899 



Hydrachnellae 273 

Limnohalacarinae Viets, 1927 
Genera: 

1. Limnohalacarus Walter, 1917 

a. Limnohalacarus s. str. 

Type. Halacarus wackeri Walter, 1914 

b. Stygohalacams Wiets, 1934 

Type. Stygohalocarus scupiensis Viets, 1934 

2. Hamohalacarus WdAiQY, \92>\ 

Type. Hamohalacariis subterraneus Walter, 1931 

3. Soldanellonyx ^2i\iQr, \9\1 

a. Soldanellonyx s. str. 

Type. Soldanellonyx chappuisi Walter, 1917 

b. Parasoldanellonyx Viets, 1929 

Type. Soldanellonyx parviscutatus Walter, 1917 

Halixodinae Viets, 1927 
Genus: 

Halixodes Brucker and Trouessart, 1900 
Type. Agaue chitonis Brucker, 1897 

Enterohalacarinae Viets, 1938 
Genus: 

Enterohalacarus Viets, 1938 

Type. Enterohalacarus minutipalpus Viets, 1938 

Astacopsiphaginae Viets, 1931 ' • " J 

Genus: 

Astacopsiphagus Wiets, 1931 

Type. Astacopsiphagus parasiticus Viets, 1931 

Discussion: Newell 1947 has summarized the ecological zones of the 
mites by subfamilies as follows. The halacarids are either predaceous 
or lichen feeders, and in three genera are parasitic. 

1. Rhomb ognathinae Viets, 1927, is principally intertidal, rarely if 
ever found in fresh water, and never lives under conditions which pre- 
clude algal growth. These mites are cosmopolitan. 

2. Actacarinae Viets, 1939, is intertidal, arenicolous, and is never 
found under conditions which preclude algal growth. It is found in the 
North Sea. 

3. Lohmannellinae Viets, 1927, is predaceous, either in marine or 
fresh water, and is probably cosmopoHtan in distribution. 



274 Acarology 

4. Limnohalacarinae Viets, 1927, is to be found in fresh water in 
Europe, Africa, and North and South America. 

5. Simognathinae Viets, 1927, is marine and is to be found in the 
Adriatic, North Sea, Irish Sea, Caribbean, and Pacific-Antarctic Ocean. 
Predaceous forms are to be found in the Bay of Biscay and the weit- 
em Indian Ocean. 

6. Enterohalacarinae Viets, 1938, is parasitic in the gut of echino- 
derms, at least in the larval and nymphal stages, and is to be found in 
the western Pacific Ocean. 

7. Halixodinae Viets, 1927, is parasitic, at least as nymphs, on gills 
of Amphineura in New Zealand. 

8. Astacopsiphaginae Viets, 1931, is parasitic, at least as nymphs, 
on gills of fresh water decapod Crustacea in Australia. 

9. Halacarinae Viets, 1927, is predaceous, principally marine, and 
rarely fresh water, and is cosmopolitan in distribution. 

10. Porohalacarinae Viets, 1933, lives in fresh or brackish water, 
and is probably cosmopolitan in distribution except in the Arctic and 
Antarctic seas. 

Reference: 

Newell, Irwin M. 1947. A systematic and ecological study of the Hala- 
caridae of eastern North America. Bull, of The Bingham Oceano- 
graphic Collection, Peabody Museum of Natural History, Yale Univ. 
10 (3): 1-232. 

Hydrovolziidae Thor, 1905 

« Figures 187, 188 

Diagnosis: Red watermites, the hydrovolziids measure from 0.80 to 
0.95 mm. long. They have a small, predorsal shield and a large post- 
dorsal shield. At the anterior, lateral margins of the postdorsal shield 
is a pair of large, lateral shields and surrounding the postdorsal shield 
is a series of small plates or shields. A double eye in a capsule is lo- 
cated in a lateral indentation of the predorsal shield (eyes are lacking 
in subterranean species). The coxae are divided into two distinct 
groups; the legs are placed laterally so that coxae in and iv stand out 
from the side of the body. There are no swimming hairs on the legs 
and the tarsal claws are smooth and sickle-like. No genital suckers are 
present. The palpi are five-segmented and simple with a clawlike end 
segment, somewhat as in Cunaxidae. 



Hydrachnellae 



275 



Genera and subgenera: 

1. Hydrovolzia Thor, 1905 

a. Hydrovolzia s. str. 

Type. Polyxo placophora Monti, 1905 

b. Hydrovolziella Viets, 1935 

Type. Hydrovolzia lata Walter, 1935 

2. Acherontacariis Wicts, 1932 

Type. Acherontacarus halacaroides Viets, 1932 





Figure 187 Hydrovolzia placophora 
(Monti). Dorsum. (After Viets 1936) 



Figure 188 Hydrovolzia placophora 
(Monti). Venter. (After Viets 1936) 



Discussion: These are nonswimming mites and can be found in 
springs and brooks of central Europe. 



Rhynchohydracaridae Lundblad, 1936 

Figures 189, 190 

Diagnosis: The body of these mites 4s strongly armored dorsally and 
ventrally. The dorsal armor consists of a large central and many small 
marginal shields. Coxal plates i reach far past the anterior end of the 
body, closing together anteriorly to form a short sclerotized tube; coxal 
plates I and ii are united. There are no swimming hairs on the legs. 
Two broad plates surround the genital opening but there are no geni- 
tal suckers. The palpus does not have spines or protuberances and the 
chelicerae are long and slender. 



276 Acarology 

Genus: 

Rhynchohydracarus Lundblad, 1936 

Type. Rhynchohydracarus testiido Lundblad, 1936 





Figure 189 Rhynchohydracarus 
testudo Lundblad, Dorsum. (After 
Lundblad 1941) 



Figure 190 Rhynchohydracarus 
testudo Lundblad. Venter. (After 
Lundblad 1941) 



Hydrachnidae Leach, 1815 

Figures 191,192 

Diagnosis: The hydrachnids are mostly red, large, globular swim- 
ming mites found in still water. Their skin has papillae and they pos- 
sess paired eyes in capsules. The plates are of different sizes (excep- 





Figure 191 Hydrachna kenyensis 
Lundblad. Dorsal plate. (After Lund- 
blad 1942) 



Figure 192 Hydrachna kenyensis 
Lundblad. Coxal plates. (After Lund- 
blad 1942) 



tion: Anohydrachna) and shapes between the eyes. The coxal plates 
are usually united in four groups of two each. There are no swimming 
hairs on the legs and the tarsal claws are smooth and sickle-like. The 
chelicerae are unsegmented and stylet-like. Movably linked in front 



Hydrachnellae 277 

the genital plates are fused medianly and have numerous small genital 
suckers. 

Genera and subgenera: 

1. Hydrachna Miiller, 1776 (= Atax Fabricius, 1805) 

a. Hydrachna s. str. (= Diplohy drachma Thor, 1916) 
Type. Hydrachna cruenta Miiller, 1776 

b. Anohydrachna Thor, 1916 

Type. Hydrachna perniformis Koenike, 1895 

c. Chitohydrachna Habeeb, 1950 

Type. Hydrachna {Chitohydrachna) ennishonenses Habeeb, 1950 

d. MonohydrachnaThoT, 1916 

Type. Hydrachna cruenta Krendowsky, 1884 

e. Rhabdohydrachna \iets, 1913 

Type. Hydrachna bisignifera Viets, 1913 

f. Schizohydrachna Thor, 1916 

Type. Hydrachna uniscutata Thor, 1897 

g. Scutohydrachna Viets, 1933 

Type. Hydrachna {Scutohydrachna) dorsoscutata Viets, 1933 
h. Tetrahydrachna Lundblad, 1934 

Type. Hydrachna globoso var. miliaria Berlese, 1888 

2. Bargena Koenike, 1893 

Type. Bargena mirifica Koenike, 1893 



Limnocharidae Kramer, 1877 

Figures 193-196 

Diagnosis: Red, nonswimming mites found in standing and slo\^ 
moving water, the limnocharids are weak-skinned. Eye capsules which 





Figure 193 Limnochares (Cyclothrix) 
nutans Lavers. Leg iv. (After Lavers 
1941) 



Figure 194 Limnochares {Cyclothrix) 
natans Lavers. Eye plate. (After 
Lavers 1941) 



278 



A carology 



lie laterally on a median, rod-shaped, sclerotized plate are present. The 
rostrum is cylindrical, broad, and situated anteriorly with a mouth disk 
and fringe. The chelicerae are extensive, united with one another, and 
cover the maxillary organ. The genital suckers are small, numerous, 
and lie free in the skin. 





Figure 195 Litnnochares aquatica 
(Linnaeus). Larva, venter. 
(After Viets 1936) 



Figure 196 Limnochares aquatica 
(Linnaeus). Larva, dorsum. 
(After Viets 1936) 



Limnocharinae Claus, 1880 

Genera and subgenera: 

1. Limnochares 1.2iiYQ'\\\Q, 1796 (= Hemitrombicula Ewing, 1938) 

a. Limnochares s. str. 

Type. Acariis aquaticiis Linnaeus, 1758 

b. Cyclothrix Wolcott, 1905 

Type. Limnochares crinita Koenike, 1898 

2. N eolimnochares hundhlsid, 1937 

Type. Neolimnochares placophora Lundblad, 1937 



Rhyncholimnochai inae Lundblad, 1936 



Genera: 



1. Rhyncholimnochares Lundblad, 1936 

Type. Rhyncholimnochares lamellipalpis Lundblad, 1936 

2. P arali mnochar e s 'LundhlB.d, 1937 

Type. Paralimnochares sursumhians Lundblad, 1937 



Hydrachnellae 



279 



Eylaidae Leach, 1815 

Figures 197, 198 

Diagnosis: These mites have a weak skin which usually lacks scle- 
rotic shields. The maxillary organ has a large mouth disk surrounded 
by a fringe. The chelicerae are separated from one another, are large 
basally, tall dorso-ventrally, and 
have a small claw. The palpi are 
usually long and richly haired. 
The coxal plates are arranged in 
four groups of two each and the 
tarsal claws are simple. Placed in 
capsules the eyes are connected 
with one another by a sclerotized 
bridge and lie dorso-medianly 





Figure 197 Eylais desecta Koenike. 
Eve plates of female. (After Marshall 
1927) 



Figure 198 Piersigia koenikei Viets. 
Dorsum. (After Viets 1936) 



forming "spectacles," or if the eyes are lateral they are on the margin 
of a many-segmented plate. 



Genus and subgenera: 



Eylainae Claus, 1880 



Eylais Latreille, 1796 

a. Eylais s. str. 

Type. Hydrachna extendens Miiller, 1776 

b. Capeulais Thor, 1 902 

Type. Capeulais crassipalpis Thor, 1902 

c. Meteylais Szalay, 1934 

Type. Eylais hamata Koenike, 1897 

d. Pareylais Szalay, 1934 

Type. Eylais setosa Koenike, 1897 

e. Proteylais Szalay, 1933 

Type. Eylais degenerata Koenike, 1897 



280 Acarology 

f. Rhy nchey lais Lundblsid, 1938 

Type. Rhyncheylais connexa Lundblad, 1938 

g. Syneylais Lundblad, 1936 

Type. Eylais infundibulifer Koenike, 1897 



Piersigiinae Oudemans, 1902 



Genus: 



Piersigia Protz, 1896 

Type. Piersigia limophila Protz, 1896 

Discussion: Lundblad 1941 lists this as a family. 



Protziidae Viets, 1926 

Figures 199. 200 

Diagnosis: These mites are red in color, have a weak skin, are papil- 
late or have striae, and usually lack true dorsal plates. Lateral eyes lie 
in capsules while a median eye may be present or lacking. The palp- 
tarsus located on the distal dorsal end of the tibia usually has a spine- 




Figure 199 Calonyx javanensis Viets. 
Tarsal claw (left), palpus (right). 
(After Lundblad 1936) 



Figure 200 Calonyx javanensis 
Viets. Venter of male. (After 
Lundblad 1936) 



like elongation. Arranged in four groups, the coxal plates are about 
equal in size, the posterior group as a rule being far toward the rear. 
The legs lack swimming hairs while the tarsal claws are sickle-like, 
simple, or many-toothed. Between the anterior and posterior groups 
of coxal plates, far from the posterior margin of the body lies the gen- 
ital organ. The usually numerous, more or less easily seen, often long- 
stalked genital suckers are in the skin, are variable in position, and 



Hydrachnellae 



281 



have button-like or acorn-like suckers posteriorly. The genital plates 
are lacking or hair-bearing. 

Genera: 

1 . Protzia Piersig, 1 897 

Type. Thy as eximia Protz, 1896 

2. Calonyx Walter, 1907 

Type. Calonyx kitiis Walter, 1907 

3 . Neocalonyx Walter, 1919 

Type. Neocalonyx godeti Walter, 1919 

4. Partnunia Piersig, 1897 

Type. Thy as angusta Koenike, 1893 

5. Partnuniella Viets, \93S 

Type. Partnuniella thermalis Viets, 1938 

6. Fro^zzW/aLundblad, 1934 

Type. Protziella hutchinsoni Lundblad, 1934 

7. Wandesia Schechtel, 1912 

Type. Wandesia thori Schechtel, 1912 



Hydrodromidae Viets, 1936 

Figures 201, 202 

Diagnosis: The hydrodromids are red in color and have weak skin 
with papillae. No dorsal shield is present. Lateral eyes are separated, 
from one another and are not contained in capsules while a median 




Figure 201 Hydrodroma despiciens 
(Miiller), Coxal and genital plates. 
(After Lundblad 1944) 



Figure 202 Hydrodroma despiciens 
(Miiller). Palpus. (After Lundblad 
1944) 



eye is lacking. The coxal plates are divided in four groups of two each. 
The legs usually have swimming hairs and the tarsal claws have small 
outer accessory teeth. The palpal tibia has a long dorsal distal process 
above the palpal tarsus. Genital plates with many suckers are present. 



282 
Genera: 



A carology 



1. Hydrodroma Koch, \%?>1 

Type. Hydrachna despiciens Miiller, 1776 (= Hydrodroma umbrata 
Koch, 1837) 

2. 0;co/7A'/5 Nordenskiold, 1905 

Type. Oxopsis diplodontoides Nordenskiold, 1905 



Hydryphantidae Thor, 1900 

Figures 203, 204 

Diagnosis: The hydryphantids are red in color. Their skin has papil- 
lae and may or may not have a frontal plate but is seldom well ar- 
mored. A median eye is present only when the frontal plate is present. 
The palpal tibia has a dorsal-distal process. The coxal plates are in 





Figure 203 Hydryphantes tenuabilis Figure 204 Hydryphantes ruber (De- 
Marshall. Anterior portion of body Geer). Venter. (After Marshall 1944) 
showing eyes and plate. (After Mar- 
shall 1946) 

four groups. All legs have swimming hairs and the tarsal claws are 
simple, sickle-like. The genital organ has two movable plates and 
three or more pairs of genital suckers. 

Hydryphantinae Piersig, 1896 

Genera and subgenera: 

1. Hydryphantes Koch, 1841 

a. Hydryphantes s. str. 

Type. Acarus aquaticus ruber DeGeer, 1778 

b. Octohydryphantes\.ux\dh\2id, 1927 

Type. Hydryphantes octoporus Koenike, 1896 



Hydrachnellae 283 

c. Polyhydryphantes Wiets, 1926 

Type. Hydrodroma fiexiiosa Koenike, 1885 

2. G6'orgW/rt Koenike, 1907 

Type. Hydrodroma helvetica Haller, 1882 

3. Papilloporiis Walter, 1935 

Type. Hydryphantes incertus Koenike, 1893 

Diplodontinae Vitzthum, 1942 
Genus: 

Diplodontiis T)ughs, 1833 (= Eupatra Koenike, 1896) 
Type. Diplodontus scapularis Duges, 1834 

Mamersinae Viets, 1931 
Genus: 

Marnersa Koenike, 1898 

Type. Marnersa testudinata Koenike, 1898 

Thyasinae Viets, 1926 

Genera and subgenera: 

1. Thy as ¥.och, 1836 

Type. Thy as venusta Koch, 1836 

2. JavathyasV'iQis, 1929 {^Allothyas W'lQis, 1929) 
Type. Javathyas triumvirorum Viets, 1929 

3. Kashmirothyas Lundblad, 1934 

Type. Kashmirothyas hutchinsoni Lundblad, 1934 

4. Lundbladia \ieXs, 1929 

a. Lundbladia s. str. 

Type. Lundbladia feuerborni Viets, 1929 

b. Octolundbladia WizXhum, 1942 

Type, Octolundbladia ladakiana Vitzthum, 1942 

5. Octothyas lAindhXdid, 19 A5 

Type. Octothyas hewithi Lundblad, 1945 

6. Panisellus Yiets, 1925 

Type. Panisus thienemanni Viets, 1820 

7. Panisoides Lundblad, 1926 
Type. Thyas setipes ViQis, 1911 

8. Panisus Koenike, I S96 

Type. Panisus michaeli Koenike, 1896 

9. Parathyas l.undb\ad, 1926 

Type. Thyas thoracatus Piersig, 1896 
10. Placothyas \^\xr\dh\2id, \926 

Type. Thyas octopora Viets, 1914 



284 Acarology 

11. Plesiothyas y\Q\%, \9?>5 

Type. Trichothyas multipora Walter, 1935 

12. Thyasella ViQis, 1926 

Type. Thy as mandihiilaris Lundblad, 1924 

13. 7/7yop^/^ Piersig, 1898 

Type. Thy as cancellata Protz, 1896 

14. Trichothyas Viets, 1926 

Type. Thy as pennata Viets, 1913 

15. F/e?5/a Lundblad, 1926 

Type. Thy as sciitata Protz, 1923 

Euthyasinae Viets, 1951 
Genera: 

1. Euthyas Piersig, 1898 {— Bradybates Neuman, 1874 nom. praeocc.) 
Type. Bradybates truncatus Neuman, 1874 

2. Panisopsis Viets, 1926 

Type. Thyas vigilans Piersig, 1896 

3. Thy asides Lundblad, 1926 
Type. Thyas dentata Thor, 1897 

4. Zschokkea Koenike, 1892 

Type. Zschokkea oblonga Koenike, 1892 

Teratothyasinae Viets, 1929 

Genus: 

Teratothyas y lets, 1929 

Type. Teratothyas reticulata Wieis, 1929 

Tartarothyasinae Viets, 1954 
Genus: 

Tartarothyas Wiets, \934 

Type. Tartarothyas micrommata Viets, 1934 

Clathrosperchonidae Lundblad, 1936 

Figures 205, 206 

Diagnosis: The body of these mites has a strong skin, which is cov- 
ered with tiny spines and a radiating network pattern on the dorsal 
and ventral surface. Projecting only weakly above the skin surface the 
skin glands are strongly sclerotized and crater-like. The rostrum is 
either long and narrow, elongate and tubelike on the anterior end 
(Clathrosperchon) , or not tubelike and relatively short (Clathrosper- 



Hydrachnellae 



285 



chonella). The cheliCerae are slender in the preceding and strong in 
the latter genus; the palpus is not shearlike. No swimming hairs are to 
be found on the legs and the tarsal claws have accessory ventral teeth. 
Two genital plates with many genital suckers are present. 









Figure 205 Clathrosperchon minor 
Lundblad. Dorsum of male. 
(After Lundblad 1941) 




Figure 206 Clathrosperchon minor 
Lundblad. Venter of male. 
(After Lundblad 1941) 



Genera: 

1. Clathrosperchon Lundblad, 1936 

Type. Clathrosperchon crassipalpisJLundhlad, 1936 

2. Clathrosperchonella hundhlad, 1937 

Type. Clathrosperchonella asterifera Lundblad, 1937 



Ctenothyasidae Lundblad, 1936 

Figure 207 

Diagnosis: The body of these mites is strongly skinned and has 
papillae but lacks armor. An apparently rudimentary median eye is 
present and the lateral eyes are single-capsuled. The skin gland areas 



266 



Acarology 



are strongly raised and wartlike. The rostrum is Thyas-VikQ; the palpal 
tibia lacks an end process. The coxal plates are divided in four groups; 

all tarsi have two simple claws and the 
legs lack swimming hairs. The outer 
genital organ of the female has two 
large, strongly sclerotized and porose 
plates with three large suckers on the 
lateral margins of each. 



Figure 207 Ctenothyas verrucosa Lundblad. 
Venter of female. (After Lundblad 1936) 




Genus: 



Ctenothyas Lundblad, 1936 

Type. Ctenothyas verrucosa Lundblad, 



1936 



Thermacaridae Sokolow, 1927 

Figures 208, 209 

Diagnosis: The body of these mites is entirely armored and the cen- 
tral dorsal shield is united with the ventral plate by a thin but strong 
suture. Two eyes lying in capsules are placed anteriorly on each side 
and a median eye is present. Coxal plates i are united medianly with- 
out any suture, but sutures separate coxal plates i, ii, iii, and iv. The 





Figure 208 Thermacarus nevadensis 
Marshall. Ventral plates of female. 
(After Marshall 1928) 



Figure 209 Theriiuictirus nevadensis 
Marshall. Dorsum of male. (After 
Marshall 1928) 



Hydrachnellae 



287 



coxal plates are contiguous. In the female the genital organ separates 
coxal plates iii and iv; in the male coxal plates iv touch medianly and 
the genital organ is posterior to these. United plates i form a cam- 
erostome into which the gnathosoma can be withdrawn. Trochanters 
I, II, and III have a strong, cuplike cavity into which the basifemora 
articulate; the tarsal claws are strongly sickle-like and lack accessory 
claws but have a sharp tooth on the concave side. There are two mov- 
able genital plates which are divided into anterior and posterior parts, 
the posterior portion having many small genital suckers. These mites 
are to be found living in hot springs. 

Genus: 

Thermacarus Sokolow, 1927 

Type. Thermacarus thermobius Sokolow, 1 927 

Discussion: These mites are to be found living in hot springs whose 
temperatures range from 42° to 46° C. 

Reference: 

Marshall, R. 1928. A new species of water mite from thermal springs. 
Psyche 35 (2) : 92-96. 



Rutripalpidae Sokolow, 1934 

Figure 210 



Diagnosis: The skin of these 
mites is weak, with a tendency to 
form sclerotized platelets or pa- 
pillae. The coxal plates are di- 
vided into four groups of two 
each. There are no swimming 
hairs on the legs; the first three 
pairs of legs have well-developed 
tarsal claws provided with many 
narrow accessory spines (on leg 
IV these accessory spines are al- 
most entirely reduced). From a 
lateral view the two end segments 
of the palps seem shovel-like and 
broadened. The fixed chela of the 
chelicera is reduced. 




Figure 210 Rutripalpus limicola Sok- 
olow. Venter. (After Sokolow 1934) 



288 
Genus: 



Acarology 



Rutripalpus Sokolow, 1934 

Type. Rutripalpus limicola Sokolow, 1934 

Mamersopsidae Lundblad, 1930 

Figures 211,212 

Diagnosis: Dorsal and ventral shields appear on the body of these 
mites and are separated from one another by a dorsal suture. The 
dorsal shield may consist of one plate or of many united plates; gland 
pore plates are located in the dorsal suture. The palpus is clublike, 





Figure 211 Mamersopsis thoracica Figure 212 Mamersopsis thoracica 
Nordenskiold. Dorsum. (After Nor- Nordenskiold. Venter. (After Nor- 
denskiold 1905) denskiold 1905) 

especially the palpfemur which is strongly thickened dorsally and pro- 
vided with spine or spine and protuberance on the inner margin. 
The palpal genu is shorter than the femur or tibia; the palpal tibia is 
strongly shortened and shorter than the femur and possesses a hair- 
bearing process on the inner margin; the palpal tarsus is spinelike 
distally. Forming one group, the coxal plates are united with the ven- 
tral plate and all plates are separated by weak sutures. The legs may 
or may not have swimming hairs; tarsus iv is often reduced and carries 
no claw or a simple one. The genital organ is more or less united or 
close to coxae iv and has two movable plates and three pairs of gen- 
ital suckers. 

Genera: 

1. Mamersopsis Nordenskiold, 1905 

Type. Mamersopsis thoracica Nordenskiold, 1905 



Hydrachnellae 289 

2. BandakiaThor, 1913 

Type. Bcindakia concreta Thor, 1913 

3. Platynmmersopsis y lets, 1914 

Type. Platymamersopsis nordenskioldi Viets, 1914 

Pseudohydryphantidae Viets, 1926 

Figure 213 

Diagnosis: The skin is weak and has no sclerotized plate, although 
weakly sclerotized muscle insertions are present. The dorsum has 
short, robust, many-pointed papillae. Lateral eyes lie in capsules and 





Figure 213 Pseudohydryphantes parvidus Viets. Female genital organ (left), 
palpus (upper right), skin papillae (lower right). (After Viets 1936) 

a median eye is also present in a small, sclerotized ring. The coxal 
plates are divided into four groups of two each; legs iii and iv have 
swimming hairs. The tarsal claws are simple and sickle-like while the 
palptibia has a dorsal distal process. The genital organ has two mov- 
able plates and three pairs of genital suckers. 

Genus: 

Pseudohydryphantes Viets, 1907 

Type. Pseudohydryphantes parvuhis Viets, 1907 

Teutoniidae Lundblad, 1927 

Figures 214, 215 

Diagnosis: The body is weak-skinned and the lateral eyes are not in 
capsules but lie near each other. No median eye is present. The palpal 
femur has a cone on the inner margin. The coxal plates are divided 
into four groups of two each; coxal plates in and iv almost form a 



290 



Acarology 



right angle; in the anterior median angle of coxal plates iv is a gland 
pore. Legs in and iv have swimming hairs and the tarsal claws of legs 
I, II, and III have accessory teeth; tarsus iv is constricted distally and 
lacks claws. 





Figure 214 Teutonia cometes (Koch). Figure 215 Teutonia cometes {Koch). 

Ventral plates of male. (After Viets Palpus (After Viets 1936) 

1936) 



Genus: 



Teutonia Koenike, 1889 

Type. Teutonia primaria Koenike, 1889 



Sperchonidae Thor, 1900 

Figures 216-218 

Diagnosis: The sperchonids have a weak or leather- 
like skin, which occasionlly has shields, with rugose or 
fine-pointed papillae in the striated area. Lateral eyes 
lie in capsules but a median eye is seldom present. The 
palpfemur has a spine-bearing peg on the inner side; 
the palpal tibia lacks distal-dorsal elongation and the 
inner side has two sensory spines. The coxal plates are 
arranged in four groups; coxal plates iv are three- or 
Figure 216 Sper- four-cornered; the legs have no swimming hairs and 
Koenike^^Genital ^^^ tarsal claws as a rule have accessory teeth. With 
plates of female, two lateral, movable plates and three pairs of genital 
suckers, the genital organ is situated more or less 
between the posterior coxal plates. 




( After 
1943) 



Marshall 



Genera and subgenera: 

1. Sperchon Kramer, 1877 
a. Sperchon s. str. 

Type. Sperchon squamosa Kramer, 1879 



Hydrachnellae 



291 



h. Hispidosperchon Thor, 1901 

Type. Sperchon hispicius Thor, 1898 

c. Mixosperchon Viets, 1926 

Type. Sperchon papillosus Thor, 1901 

d. Scutosperchon Viets, 1926 

Type. Sperchon thori Koenike, 1900 
Sperchonopsis Piersig, 1896 (= Pseudosperchon Piersig, 1901) 
Type. Sperchon verrucosus Protz, 1896 





Figure 217 Sperchonopsis verrucosa 
(Protz). Venter of male. (After Mar- 
shall 1943) 



Figure 218 

Palpus of 
1936) 



Sperchon cornutiis Viets. 
male. (After Lundblad 



Anisitsiellidae Viets, 1929 

Figures 219, 220 

Diagnosis: The body of these mites is weak-skinned or armored and 
has a dorsal suture. Lateral eyes are not placed in capsules, but are 
separated from each other. The inner side of the palpal femur has a 
process. Coxal plate iv does not have a large gland pore on the an- 
terior median corner; tarsi iv are reduced distally and lack claws. The 
genital organ has two movable plates and three or four pairs of genital 
suckers. 



Anisitsiellinae Koenike, 1910 



Genera. 



1. 



Anisitsiella Daday, 1905 
Type. Anisitsiella aculeata Daday, 1905 
2. Hydrobaumia Halik, 1930 

Type. Hydrobaumia malacensis Halik, 1930 



292 



Acarology 



5. 



Mamersella Viets, 1929 

Type. Mamersella thienemanni Viets, 1929 

Mamersellides Lundblad, 1937 

Type. Mamersellides ventriperjoratiis Lundblad, 1937 

Mamersides Viets, 1935 

Type. Mamersides saranganensis Viets, 1935 

Mamersopides Viets, 1916 

Type. Mamersopides sigthori Viets, 1916 

Rutacarus \.undh\^.d, 1937 

Type. Rutacarus pyriformis Lundblad, 1937 

Sigthoria Koenike, 1907 (= Amasis Nordenskiold, 1905 nom. 

praeocc.) 
Type. Amasis niloticus Nordenskiold, 1905 





Figure 219 Mamersellides ventriper- 
foratus Lundblad. Dorsum of female. 
(After Lundblad 1941) 



Figure 220 Mamersellides ventriper- 
foratus Lundblad. Venter of female. 
(After Lundblad 1941) 



Nilotoniinae Viets, 1929 

Genera and subgenera: 

1. NilotoniaJhov, 1905 

Type. Teutonia loricata Nordenskiold, 1905 

2. Dartia Soar, 1917 

a. Dartia s. str. 

Type. Dartia harrisi Soar, 1917 

b. Dartiella Viets, 1929 

Type. Dartia longipora Walter, 1925 

3. Dartonia Viets, 1929 

Type. Dartonia caerulea Viets, 1929 

4. Kawamuracariis Uchida, 1937 

Type. Kawamuracariis elongatus Uchida, 1937 



Hydrachnellae 



293 



7. 



Limnolegeria Motas, 1 928 

Type. Limnolegeria longiseta Motas, 1928 

Manotonia Viets, 1935 (= Mania Walter, 1935 nom. praeocc.) 

Type. Mania muscicola Walter, 1935 

Ranautonia \ \Qis, \929 

Type. Ranautonia dentipalpis Viets, 1929 



Leber tiidae Thor, 1900 

Figure 221 



Diagnosis: The lebertiids are char- 
acterized by a weak to leather-like 
skin, a dorsum which as a rule has 
no shield, and a venter which often 
has extensive sclerotization. Lat- 
eral eyes are paired in a weak, scle- 
rotized capsule. The palpus is more 
or less slender or narrow. All coxal 
plates are united in one group and 
a median suture is often lacking. 
The genital organ has two plates 
and three pairs of genital suckers, 
although in many cases only two 
pairs are present. 




Figure 221 Lebertia qiiinque maculosa 
Marshall. Venter. (After Marshall 
1932) 



Lebertiinae Wolcott, 1905 

Genus and subgenera: 

Lebertia Neumann, 1880 

a. Lebertia s. str. (= Neolebertia Thor, 1905) 
Type. Pachygaster tau-insignatus Lebert, 1879 

b. Distolebertia Husiatinschi, 1937 

Type. Distolebertia bucovinensis Husiatinschi, 1937 

c. Hexalebertia Thor, 1906 

Type. Lebertia stigmatifera Thor, 1900 

d. Mixolebertia Thor, 1906 

Type. Lebertia brevipora Thor, 1899 

e. Pilolebertia Thor, 1900 

Type. Lebertia insignis Neumann, 1880 

f. Pseudolebertia Thor, 1897 

Type. Pseudolebertia glabra Thor, 1897 



294 



Acarology 



Oxinae Viets, 1926 
Genera and subgenera: 

1. Oxus Kramer, 1877 

a. Oxus s. str. 

Type. Oxus ohlongus Kramer, 1879 

b. Pseudoxusi:\\ox, 1901 

Type. Pseudoxus integer Thor, 1901 

2. Frontipoda Koenike, 1891 

Type. Hydrachna musculus Mliller, 1776 

3. Gnaphiscus Koenike, 1898 

a. Gnaphiscus s. str. 

Type. Gnaphiscus setosus Koenike, 1898 

b. Gnaphoxus Thor, 1913 

Type. Gnaphiscus (Gnaphoxus) ekmani Thor, 1913 

Atractideidae Thor, 1902 

Figures 222, 223 

Diagnosis: In the atractideids the ventral shield is entire while the 
dorsal shield is divided into several plates by sutures. In general the palpi 
are small; the palpal femur and tibia frequently have spines or cones on 





Figure 222 Atractides sierrensis Mar- 
shall. Venter of male. (After Marshall 
1943) 



Figure 223 Atractides sierrensis Mar- 
shall. Dorsum of male. (After Mar- 
shall 1943) 



the inner margin. Coxal plates i lack a median suture and are united; 
a suture separating coxal plates ii and in is more or less lacking and 
coxal plates iv posteriorly and outwardly are not well separated from 
the ventral shield. The legs have no swimming hairs and the tarsal 



Hydrachnellae 



295 



claws have accessory teeth. The genital organ has two movable plates 
and with three or six pairs of genital suckers. 

Genera and subgenera: 

1. Atractides Koch, \S31 

a. Atractides s. str. 

Type. Atractides anomcdus Koch, 1837 

b. Monatractides Viets, 1926 

Type. Atractides uniscutatus Viets, 1925 

c. Rusetria Thov, 1897 

Type. Rusetria spinirostris Thor, 1897 

d. Rusetriella Wieis, 1931 

Type. Atractides acutiscutatiis Viets, 1913 

2. Pseudotorrenticola Walter, 1906 

Type. Pseudotorrenticola rhynchota Walter, 1906 

3. Testudacarus Walter, 1928 

Type. Testudacarus tripeltatus Walter, 1928 

Pontarachnidae Thor, 1929 

Figure 224 



Diagnosis: These mites are ocean 
livers and do not have any tracheal 
system. The coxal plates are di- 
vided into two groups of four each. 
The genital organ has no movable 
plates or genital suckers and the 
palpi are simple and lack inner 
protuberances. 



Figure 224 Pontaraclina punctulum 
Philippi. Venter of female. (After 
Walter 1925) 




Genera: 

1. Pontarachna Philippi, 1840 

Type. Pontarachna punctulum Philippi 

2. Z./mrac/z«fl Walter, 1925 

Type. Litarachna incerta Walter, 1925 



1840 



296 Acarology 

Neotorrenticolidae Lundblad, 1936 

Figures 225, 226 

Diagnosis: These mites have a soft skin and eyes which are sepa- 
rated. The dorsum of the male is entirely armored while the dorsum 
of the female has many small, sclerotized plates. The palpus has hair- 
bearing protuberances on the tibia and a spine-bearing tooth on the 





Figure 225 Neotorrenticola violacea 
Lundblad. Venter of young female. 
(After Lundblad 1942) 



Figure 226 Neotorrenticola violacea 
Lundblad. Palpus. (After Lundblad 
1942) 



femur. In the male the coxal plates are united but in the mature female 
they are separated into four groups. In the immature female the coxal 
plates are approximate. The legs are long and strong without swim- 
ming hairs but with strong and weak spines. The tarsal claws are large 
and have ventral accessory teeth. Many genital suckers surround the 
genital organ. 

Genus: 

Neotorrenticola Lundblad, 1936 

Type. Neotorrenticola violacea Lundblad, 1936 

References: 

Lundblad, O. 1936. Dritte Mitteilung uber Wassermilben aus Santa Catha- 

rina in Siidbrasilien, Zool. Anz. 116:200-211. 
. 1942. Die Hydracarinenfauna Sudbrasiliens und Paraguays — II. K. 

Svenska Vetensk Akad. Handl. 20(3) :3-175. 



HydracJmellae 



297 



Limnesiidae Thor, 1900 

Figures 227, 228 

Diagnosis: Usually weakly skinned, the body of these mites is smooth, 
has no papillae, and is seldom entirely armored. A small, unpaired 





Figure 227 Centrolimnesia bondi Lundblad. Leg ill (left), leg iv (right) (After 
Lundblad 1935) 



\ 



shield, or two shields, is located posteriorly on the dorsum. Lateral 
eyes are separated from one another and lie singly. The palpal femur 
usually has a peg or small spine 
on the inner side while the palpal 
tibia has a small seta on the inner 
side. The coxal plates are arranged 
in four groups of two each and 
are seldom united into one group; 
coxal plates iv are large and tri- 
angular with the acetabula on the 
posterior lateral edge. The legs 
usually have swimming hairs and 
tarsi IV as a rule are reduced and 
lack claws. The genital organ is 
close to the coxal plates; the geni- 
tal plates have three, but seldom 
four or more suckers. In the male 

the genital plates are united with V^Zl!^^ Centrolimnesia bondi 

^ ^ Lundblad. Venter of male. (After 

one another. Lundblad 1935) 




298 Acarology 

Limnesiinae Koenike, 1^09 

Genera and subgenera: \ 

1. Limnesia Koch, 1836 

a. Limnesia s. str. 

Type. Limnesia fulgida Koch, 1836 

b. Allolimnesia Viets, 1936 

Type. Allolimnesia polypora Viets, 1936 

c. Limnesiopsides Viets, 1938 

Type. Limnesiopsides pectungulatus Viets, 1938 

d. Limnesiopsis Piersig, 1897 

Type. Limnesia anomala Koenike, 1895 

e. Neolimnesia Lundblad, 1936 

Type. Limnesia {Neolimnesia) plaumanni Lundblad, 1936 

f. Paralimnesia Lundblad, 1938 

Type. Limnesia {Paralimnesia) microdon Lundblad, 1938 

g. Tetralimnesia Thor, 1923 

Type. Limnesia aspera Koenike, 1898 

2. Centrolimnesia Lundblad, 1935 

Type. Centrolimnesia bondi Lundblad, 1935 

3. Duralimnesia Viets, 1923 

Type. Duralimnesia tenuipalpis Viets, 1923 

4. Limnesiella Daday, 1905 

a. Limnesiella s. str. 

Type. Limnesiella pusilla Daday, 1905 

b. Limnesielluta Viets, 1935 

Type. Limnesiellula brasiliana Viets, 1935 

5. Limnesicula Viets, 1937 

Type. Limnesicula verrucosa Viets, 1937 

6. Pilolimnesia Viets, 1938 

Type. Pilolimnesia rostrata Viets, 1938 

7. Tubophora Walter, 1935 

Type. Tubophora limnesioides Walter, 1935 

Protolimnesiinae Viets, 1940 

Genera: 

1. Protolimnesia Lundblad, 1927 

Type. Limnesia unguiculata Walter, 1919 

2. Crenolimnesia Lundblad, 1938 

Type. Crenolimnesia placophora Lundblad, 1938 

3. Limnesides Lundblad, 1936 

Type. Limnesides epimerata Lundblad, 1936 



Hydrachnellae 



299 



Tyrelliinae Koenike, 1910 



Genera: 



1. Tyrellia Koenike, 1895 

Type. Tyrellia circiilaris Koenike, 1895 

2. Neotyrellia Lundblad, 1938 

Type. Neotyrellia petricola Lundblad, 1938 



Hygrobatidae Koch, 1842 

Figure 229 

Diagnosis: As a rule the body of these 
mites is weak-skinned. The palpal femur 
often has processes on the inner side while 
the anterior inner margin of the palpal 
femur is often toothed. There are small 
setae on the inner side of the palpal tibia, 
and often a median, swordlike setae is 
present. The coxal plates usually lie in 
three groups (the coxal plates i are united 
behind the maxillary organ); the plates 
are seldom in four groups of two each or 
all united with one another. Coxal plates 
I, II, and III are usually narrow and elon- 
gated, while plate iv is large. The suture 
between plates in and iv usually does not 

reach the inner margin of the group. Usually the legs have no swimming 
hairs and seldom do they have separate, long hairs. The genital organs 
have plates and as a rule three pairs of suckers (they seldom have fewer 
or more suckers). The male has a roundish plate with a more or less 
splitlike sexual opening while the female has two (seldom four) sepa- 
rate plates. 




Figure 229 Hygrobates ple- 
hejus Lundblad. Venter of 
male. (After Lundblad 1930) 



Hygrobatmae Claus, 1880 
Genera and subgenera: 

1. Hygrobates Koch, 1837 

a. Hygrobates s. str. 

Type. Hydrachna longipalpis Hermann, 1804 

b. Capobates Jhor, 1898 

Type. Capobates sarsi Thor, 1898 



300 Acarology 

c. Dekabates Thor, 1923 

Type. Hygrubates decaporus Koenike, 1895 

d. DiktyobatesJhor, 1927 

Type. A cams fluviatilis Strom, 1768 

e. Dodeccibates Vieis, 1926 

Type. Hygrobates dodecaponis Koenike, 1895 

f. Monobates Walter, 1935 

Type. Hygrobates falcipalpis Koenike, 1907 

g. Neohygrobates Viets, 1935 

Type. Neohygrobates puheruhis Viets, 1935 
h. Rhabdotobates Thor, 1927 

Type. Hygrobates calliger Piersig, 1896 
i. Rivobateslhov, 1897 

Type. Rivobates norvegicus Thor, 1897 
j. Tetrabates Thor, \913> 

Type. Hygrobates octoporus Daday, 1913 

2. Corticacarelliis Lundblad, 1937 

Type. Corticacariis labialis Lundblad, 1936 

3. Corticacarus Lundblad, 1936 

Type. Corticacarus dentipalpis Lundblad, 1936 

4. Crenohygrobates Lundblad, 1938 

Type. Crenohygrobates multiporus Lundblad, 1938 

5. Hygrobatella Viets, 1926 (= Placohates Lundblad, 1927) 
Type. Hygrobates placophorus Walter, 1919 

6. Hygrobatides Lundblad, 1936 

Type. Hygrobatides pachy dermis Lundblad, 1936 

7. Hy grobatopsis V\cis>, \92A 

Type. Hygrobatopsis levipalpis Viets, 1924 

8. Kyphohygrobatella Lundblad, 1936 

Type. Kyphohygrobatella serratipaipis Lundblad, 1936 

9. Kyphohygrobates Viets, 1935 

Type. Hygrobates verrucifer Daday, 1905 

10. Megabates\\Qis,\91A 

Type. Megabates rectipes Viets, 1924 

11. Paraschizobates lAmdhXdid, 1937 

Type. Paraschizobates megapoides Lundblad, 1937 

12. Schizobatesl\\ov,\921 

Type. Hygrobates disiunctus Walter, 1 924 

13. Schiibartella Wieis, 1931 

Type. Schubartella longipes Viets, 1937 

14. Stylohy grohates Weis, \9?>5 

Type. Stylohygrobates longipalpis Viets, 1935 

15. Subcorticacariis 'LundhX^id, 1937 

Type. Subcorticacarus digitatus Lundblad, 1937 



I 



Hydrachnellae 301 

16. Thonia Halik, 1941 

Type. Thonia harbata Halik, 1941 

17. Thoracohygrobates Lundblad, 1936 

Type. Thoracohygrobates cancellatus Lundblad, 1936 



INIegapusinae Thor, 1927 

Genera and subgenera: 

1. M^^fl/7M5 Neumann, 1880 

a. Megapus s. str. 

Type. Atractides spinipes Koch, 1837 

b. Octomegapus Viets, 1926 

Type, Megapus octoporus Piersig, 1904 

c. Poly megapus Viets, 1926 

Type. Megapus polyporus Viets, 1922 

d. Tetramegapus Viets, 1926 

Type. Megapus gabretae Thon, 1901 

e. Tympanomegapus Thor, 1923 

Type. Atractides pavesii Maglio, 1905 

2. Hygrobatomegapus Lundblad, 1927 

Type. Hygrobatomegapus spathuliferus Lundblad, 1927 

3. Megapella Lundblad, 1936 

Type. Megapella longimaxillaris Lundblad, 1936 

4. Megapoides Lundblad, 1936 

Type. Megapoides porosus Lundblad, 1936 

5. Mesobatella Nitis, i9^i 

Type. Megapus serratisetus Viets, 1916 

6. Mesobates Thov, 1901 

Type. Mesobates forcipatus Thor, 1901 

7. Mixobates Thov, 1905 

Type. Mixobates processifer Thor, 1905 

Atractidellidae Lundblad, 1936 

Figures 2^0-233 

Diagnosis: With shields on the anterior dorsum, the body of these 
mites is strongly skinned. The chelicerae are long and slender and the 
palpal femur and genu each have a ventral spine. The coxal plates he 
in three groups; the two anterior pairs of plates are united behind the 
maxillary organ, coxal plate iv has a sclerotized posterior margin which 
is drawn out into a hooklike projection, and the anterior portion of 
coxal plates i surpasses the edge of the body. The legs are long and 



302 



A carology 



have no swimming hairs. The genital organ has two plates and three 
pairs of genital suckers. 




Figure 230 Atractidella hamata 
Lundblad. Venter of female. (After 
Lundblad 1942) 




Figure 231 Atractidella hamata 
Lundblad, Palpus of female. (After 
Lundblad 1942) 



Genera: 

1. Atractidella Lundblad, 1936 

Type. Atractidella hamata Lundblad, 1936 

2. Atractidopsis Lundblad, 1936 

Type. Atractidopsis digitata Lundblad, 1936 




Figure 2J2 Atractidella hamata 
Lundblad. Dorsum of male. (After 
Lundblad 1942) 




Figure 233 Atractidella hamata 
Lundblad. Dorsum of female. (After 
Lundblad 1942) 



Rejerence: 

Lundblad, O. 1936. Neue Wassermilben aus Santa Catharina in Siidbra- 
silien. Zool. Anz. 115:29-51. 



Hydrachnellae 



303 



Nautarachnidae Viets, 1935 

Figure 234 



Diagnosis: These mites have a strong 
skin which has papillae. Lateral eyes 
lie in capsules. The chelicerae are two- 
segmented. The palpus has no peglike 
processes and the palpal tibia lacks 
sclerotized pegs distally. The coxal 
plates lie in four groups of two each; 
coxal plate iv has a posteriorly directed 
process on the median posterior mar- 
gin. The legs have swimming hairs. The 
genital organ has two lateral, long, 
many-suckered plates. 



Genus: 




Figure 234 Nautarachna crassa 
(Koenike). Venter of female. 
(After Viets 1936) 



Nautarachna Moniez, 1888 

Type. Nautarachna asperrimum Moniez, 1888 



Feltriidae Thor, 1929 

Figures 235-237 

Diagnosis: The body skin of these 
mites is more or less plainly striated. In 
the male there are no large, sclerotized 
plates or shields while in the female 
there are small, sclerotized plates or 
shields. The coxal plates lie in four 
groups of two each. In the male the 
coxal plates are often very close to each 
other; coxal plates iv are laterally broad- 
ened and often lack a true medial mar- 
gin; the posterior margin of coxal plate 
IV is transverse. No swimming hairs are 
present on the legs and tarsi in of the 
male is usually sexually differentiated. 
The genital organ is extensive or large, 
with many small, porelike suckers; the 




Figure 235 Feltria zschokkei 
Koenike. Venter of female. 
(After Viets 1936) 



304 Acarology 

sucker plates of the male are united with one another and with the 
small sexual opening. 



Genera and subgenera: 

1. Feltria Koenike, 1892 

a. Feltria s. str. 

Type. Feltria miniita Koenike, 1892 

b. Feltriella Viets, 1930 

Type. Feltria rubra Piersig, 1898 

c. Mesofeltria Uchida, 1934 

Type. Feltria {Mesofeltria) torrenticola Uchida, 

2. KongsbergiaThor, 1^99 

Type. Kongsbergia materna Thor, 1899 



1934 





Figure 236 Feltria miniita Koenike. 
Venter of male. (After Viets 1936) 



Figure 237 Feltria miniita Koenike. 
Dorsum of female. (After Viets 1936) 



Unionicolidae Oudemans, 1909 

Figure 238 

Diagnosis: The skin is usually weak but at times may be solid, strong, 
and in some genera also more or less weakly armored. Usually the skin 
is smooth and has no roundish papillae; the skin glands are often cone- 
like. The palpal femur and genu as a rule lack inner processes. Fre- 
quently the genu has long, lateral spines while the palpal tibia has a 



Hydrachnellae 



305 



spine on the distal, inner margin. The coxal plates lie in four groups of 
two each but are also united with one another and to the ventral shield. 
The anterior coxal plate group has a more or less long, posteriorly 
directed, subcutaneous process which often reaches to the posterior 
coxal plates. Posterior plates, especially iv, as a rule are rectangular 
and large. Legs i or legs i and ii are 
often thickened and often have 
paired, swordlike setae on protuber- 
ances. Usually the legs have swim- 
ming hairs. The genital organ has a 
weak-skinned form with two geni- 
tal plates; females of certain genera 
have four plates and have not under 
five or six pairs and often more 
genital suckers (the suckers seldom 
lie free in the skin). The genital 
organ of the armored forms has 
two or more weakly differentiated ^. ,,o xr • t j 

•^ Figure 238 Neumania ciirvipes Lund- 

genital plates and many suckers. blad. Venter. (After Lundblad 1930) 




Unionicolinae Koenike, 1909 



Genera and subgenera: 

1. Unionicola Haldeman, 1842 

a. Unionicola s. str. 

Type. Acarus ypsilophorus Bonz, 1783 

b. Atax Koch, 1842 (= Hexatax Thor, 1926) 
Type. Hydrachna crassipes Miiller, 1776 

c. Pentatax Thox, 1926 

Type. Atax bonzi Claparede, 1868 

d. PolyataxWiQis, 1933 

Type. Poly atax japonicus Viets, 1933 

e. Unionicolides Lundblad, 1937 

Type. Unionicola {Unionicolides) 5/cfl Lundblad, 

2. ^race//« Lundblad, 1937 

a. A tacella s. str. 

Type. Atacella clathrata Lundblad, 1937 

b. Atacellidesl^ux\dh\?id, 1941 
Type. Atax rugosus Koenike, 1890 

3. Polyatacides Lundblad, 1941 

Type. Unionicola prominens Koenike, 1914 



1937 



306 Acarology 

Encentridophorinae Viets, 1935 
Genus: 

Encentridophorus Piersig, 1897 
Type. A tax spinifer Koenike, 1893 

Huitfeldtiinae Viets, 1924 
Genus: 

HuitfeldtiaThoT, 1898 

Type. Huitfeldtia rectipes Thor, 1898 

Najadicolinae Viets, 1935 
Genus: 

Najadicola Piersig, 1 897 

Type. Atax ingens Koenike, 1895 

Neumaniinae Viets, 1931 

Genera and subgenera: 

1. Neiimania Lehert, 1S19 

a. Neiimcmia s. str. 

Type. Hydrachna spinipes Miiller, 1776 

b. Lemienia Koenike, 1910 

Type. Atax multiporus Daday, 1901 

c. Tetraneumania Lundblad, 1930 

Type. Neumania {Tetraneumania) cf/rv/pe^ Lundblad, 1930 

2. Amazonella Lundblad, 1930 

Type. Amazonella ribagai Lundblad, 1930 

3. £cpo/wA Koenike, 1898 

a. Ecpolus s. str. 

Type. Ecpolus tuberatus Koenike, 1898 

b. Subneumania Viets, 1930 

Type. Subneumania dura Viets, 1930 

4. Koenikea V^o\coii,l90<d 

a. Koenikea s. str. 

Type. Koenikea concava Wolcott, 1900 

b. Diplokoenikea l^undhlad, 1936 

Type. Koenikea (Diplokoenikea) pectinata hundhlsid, 1936 

c. Ecpolopsis Piersig, 1906 

Type. Ecpolopsis multiscutata Piersig, 1906 

d. Koenikella Lundblad, 1936 

Type. Koenikea {Koenikella) crassipalpis Lundblad, 1936 



r 



( 



Hydrachnellae 307 

e. Monokoenikea Lundblad, 1941 

Type. Koenikea melini Lundblad, 1930 

f. Neokoenikea Lundblad, 1936 

Type. Koenikea {Neokoenikea) armipes Lundblad, 1936 

g. Nyangalla Viets, 1935 

Type. Koenikea acanthophora Viets, 1935 
h. Parakoenikea Lundblad, 1936 

Type. Koenikea {Parakoenikea) curvipalpis Lundblad, 1936 
i. Pseudokoenikea Lundblad, 1941 

Type. Koenikea rutae Lundblad, 1930 
j. Recifella Viets, 1935 

Type. Recifella laminipes Viets, 1935 
k. Tcnaognathella l^undhXdid, 1941 

Type. Koenikea marshallae Viets, 1930 
1. Tanaognathus Wolcott, 1900 

Type. Tanaognathus spinipes Wolcott, 1900 
5. Leptopterotrichophorus Viets, 1914 

Type. Leptopterotrichophorus verrucosus Viets, 1914 

Pionatacinae Viets, 1916 
Genus: 

Pionatax Viets, 1916 

Type. Pionatax uncipes Viets, 1916 

Pollicipalpinae Viets, 1925 
Genus: 

Pollicipalpus Viets, 1924 

Type. Pollicipalpus scutatus Viets, 1924 

Schadeellinae Lundblad, 1938 

Genus: 

Schadeella Lundblad, 1938 

Type. Schadeella crassipalpis Lundblad, 1938 

Pionidae Thor, 1900 

Figures 239, 240 

Diagnosis: The body as a rule is weak-skinned, has no papillae, and 
seldom has shields. The chelicerae are not united with one another. 
The palpal tibia has small setae and usually protuberances on the inner 
margin and also a sclerotized peg on the distal-median end. The coxal 
plates lie in four groups of two each; in the male the plates are often 



308 Acarology 

close to one another or more or less united with one another. Coxal 
plate IV has a more or less long, subcutaneous process on the posterior 
margin while the concave posterior margins of coxal plates iv form the 
boundary of the genital indentation. The legs usually possess swimming 




Figure 239 Tiphys torris var. ameri- 
caniis Marshall. Leg iv of male. (After 
Marshall 1937) 



Figure 240 Fiona inter rnpta Mar- 
shall. Venter of female. (After Mar- 
shall 1937) 



hairs and the -tarsal claws usually have accessory teeth. The genital 
organ has plates and six or more suckers. The suckers are seldom 
located in the skin. In the male the sucker plates are usually united 
with one another. The leg structure of the male usually shows sexual 
differentiation. 

Pioninae Wolcott, 1905 

Genus and subgenera: 

Fiona Koch, 1836 

a. Fiona s. sir. 

Type. Hydrachna fuscata Hermann, 1 804 

b. Dispersipiona Viets, 1926 

Type. Hydrachna clavicornis Muller, 1776 

c. Tetrapiona Viets, 1926 

Type. Nesaea variabilis Koch, 1836 



Foreliinae Viets, 1926 



Genera: 



1. ForW/fl Haller, 1882 

Type. Hydrachna liliacca Muller, 1776 

2. Pseudofehria Soar, 1904 

Type. Pseudofehria scourfieldi Soar, 1 904 



Hydrachnellae 309 

Pionellinae Viets, 1937 



Genus: 



Pionella Viets, 1937 

Type. Pionella karamani Wiets, 1937 

Tiiihysinae Vitzthum, 1942 

Genera and subgenera: 

1. Tiphys Koch, 1836 

a. Tiphys s. str. (= Acercus Koch, 1842) 
Type. Tiphys sagulatus Koch, 1837 

b. Acercopsis Viets, 1926 

Type. Acercus pistillifer Koenike, 1908 

c. Pionides Thor, 1901 

Type. Piona ensifera Koenike, 1895 

2. Hydrochoreutes Koch, IS31 
Type. Spio ephippiata Koch, 1836 

3. Pionacercus V\eY?>\g, \^9A 

a. Pionacercus s. str. 

Type. Pionacercus leuckarti Piersig, 1894 

b. Pionacercopsis Viets, 1936 
Type. Tiphys vatrax Koch, 1837 

4. Pionopsis Piersig, 1 894 

Type. Hydrachna lutescens Hermann, 1804 

5. Wettina Piersig, 1892 

Type. Tiphys podagricus Koch, 1837 (= Wettina macroplica Piersig, 
1892) 

Astacocrotonidae Thor, 1927 

Figure 241 

Diagnosis: Astacocrotonids are parasitic in crab gills. Their skin is 
weak and has no dorsal plates. In all probability there are no skin 
pores, stigma, or trachea either. In the male eyes are present while 
there are none in the mature female. The gnathosoma lies free between 
the widely separated coxal plates i; all coxal plates are united on each 
side and are contiguous. On each coxal plate iv a large gland appears 
as shown in the figure. In the female the palpi are for grasping gill fila- 
ments; the palpi are very short and thick — thicker than the legs. No 
swimming hairs are on the legs and the tarsal claws are tridentated. 



310 Acarology 

The female genital opening is on the rear, far from the coxal plates; 

on each side is a genital plate with a longitudinal row of four genital 

suckers. The male genital opening 
lies between the two coxal plate 
groups. These mites have also 
been reported on the gills of Amia 
(Pisces; Bowfin). 




Figure 241 Astacocroton moUe Has- 
well. Venter of female. (After Haswell 
1922) 



Genus: 

Astacocroton Haswell, 1922 

Type. Astacocroton molle Haswell, 1922 

Axonopsidae Viets, 1929 

Figures 242, 243 

Diagnosis: The body is armored, porose, and has a dorsal suture. 
The coxal plates are united in one group; coxal plates i are united 
medianly with one another. The palpal tibia may or may not have inner 





Figure 242 Axonopsella spinigera 
Lundblad. Dorsum of female. (After 
Lundblad 1930) 



Figure 243 Axonopsella spinigera 
Lundblad. Venter of female. (After 
Lundblad 1930) 



Hydrachnellae 311 

protuberances. There are usually three or four pairs of genital suckers. 
Swimming hairs may or may not be present on the legs. 

Axonopsinae Viets, 1929 

Genera and subgenera: 

1. Axonopsis Piersig, 1893 

a. Axonopsis s. str. 

Type. Hydrachna complanata Mliller, 1781 

b, Hexaxonopsis Viets, 1926 

Type. Axonopsis violacea Viets, 1911 

2. Axonopsalbia Viets, 1913 

a. Axonopsalbia s. str. 

Type. Axonopsalbia curvisetifera Viets, 1913 

b. Swnatralbia Viets, 1929 

Type. Sumatralbia nigosa Viets, 1929 

3. Axonopsella Lundblad, 1930 

a. Axonopsella s. str. 

Type. Axonopsella spinigera Lundblad, 1930 

b. Neoaxonopsella Lundblad, 1937 

Type. Axonopsella {N eoaxonopsella) trifida Lundblad, 1937 

c. Paraxonopsella Lundblad, 1937 

Type. Axonopsella {Paraxonopsella) filunguis Lundblad, 1937 

4. Barbaxona Viets, 1924 

Type. Barbaxona barbata Viets, 1924 • 

5. Brachypoda Lebert, 1879 

a. Brachypoda s. str. 

Type. Hydrachna versicolor Muller (= Brachypoda paradoxa Le- 
bert, 1879) 

b. Hemibrachypoda Viets, 1937 

Type. Brachypodella mutila Walter, 1928 

c. Parabrachypoda Viets, 1929 (= Brachypodella Viets, 1926) 
Type. Brachypoda montii Maglio, 1924 

6. Kalobrachypoda Viets, 1929 

Type. Kalobrachypoda rhopalopoda Viets, 1929 

7. Lethaxona Viets, 1932 

Type. Lethaxona pygmaea Viets, 1932 

8. LjaniaThoT, 1898 

Type. Ljania bipapillata Thor, 1898 

9. Miraxona Lundblad, 1936 

a. Miraxona s. str. 

Type. Miraxona clavipes Lundblad, 1936 

b. Miraxonella l.undh\3.d, 1936 

Type. Miraxona (Miraxonella) complicata Lundblad, 1936 



312 Acarology 

10. Miraxonides Lundblad, 1938 

Type. Miraxonides alatci Lundblad, 1938 

1 1. Neoalbia Lundblad, 1936 

a. Neoalbia s. str. 

Type. Neoalbia vlolacea Lundblad, 1936 

b. Pentalbia Lundhl'dd, 1937 

Type. Neoalbia (Pentalbla) walterl Lundblad, 1936 

12. Neoaxona Lundblad, 1936 

a. Neoaxona s. str. 

Type. Neoaxona oblonga Lundblad, 1936 

b. Lamellaxona Lundblad, 1937 

Type. Neoaxona {Lamellaxona) abnormlpes Lundblad, 1937 

13. N eoaxonopsls l^undhXad, 1938 

Type. Neoaxonopsis odontogaster Lundblad, 1938 

14. Neobrachypoda Koenike, 1914 

Type. Axonopsls (?) ekmanlV^AiQv, 1911 

15. Submlraxona Lundblad, 1937 

Type. Submlraxona crasslpes Lundblad, 1937 

Albiinae Viets, 1925 

Genera: 

1. AlblaThon, 1899 

Type. Albla statlonls Thon, 1899 

2. Parasltalbla \\Qi?>,\93>5 

Type. Parasltalbla siimatrensls Viets, 1935 

3. Subalbla Weis, 1913 

Type. Subalbla procerlpalpls Viets, 1913 

Aturinae Wolcott, 1905 

Genera and subgenera: 

1. A turns Kramer, 1875 

a. A turns s. str. 

Type. A turns scaber Kramer, 1875 

b. Crlnaturus Thor, 1930 

Type. Aturus mirabills Piersig, 1897 

c. Subaturus Viets, 1916 

Type. Subaturus sulcatus Viets, 1916 

2. Aturides hundblad, 1931 

Type. Subaturus dentatus Lundblad, 1936 

3. HjartdallaThoT, 1901 

Type. Hjartdalla runclnata Thor, 1901 

4. Pseudokongsbergla y^aXiQV, \9?>5 

Type. Pseudokongsbergla longipalpis Walter, 1935 



Hydrachnellae 313 

Frontii)odopsinae Viets, 1931 



Genus: 



Frontipodopsis Walter, 1919 

Type. Frontipodopsis staheli Walter, 1919 

Mideidae Viets, 1929 

Figures 244, 245 

Diagnosis: The mideids have a highly arched body which is armored 
and has a dorsal suture. The palpal femur and genu are strong while 
the tibia is thin, narrow, longer than the femur and genu combined, 
and lacks inner protuberances. The coxal plates are combined in one 
group; coxal plates i are united medianly and coxal plates iv are tri- 





Figure 244 Midea expansa Marshall. Figure 245 Midea expansa Marshall. 
Ventral plates. (After Marshall 1940) Dorsum. (After Marshall 1940) 

angular in shape. Legs ii, iii, and iv have swimming hairs. Tarsi iii 
of the male are clasping organs. The genital indentation is large, reach- 
ing to the rear of coxae i; the genital organ is located between coxal 
plates IV. In the female the genital organ has sickle-like, sucker-bear- 
ing plates each with from five to seven pairs of suckers. In the male 
each plate has five to six pairs of suckers. The genital plates of the 
male have a three-cornered, movable, sclerotized wing. 



Genus: 



Midea Bruzel., 1854 

Type. Hydrachna orhicidata Mliller, 1776 



314 



Acarology 




Figure 246 Mideopsella 
forficicalpis Lundblad. 
Venter of female. (After 
Lundblad 1943) 



Mideopsidae Thor, 1928 

Figure 246 

Diagnosis: The body of these mites is more 
or less flattened, armored, and has a dorsal 
suture. Usually the dorsal shield is in one 
piece. The palpal tibia is shorter than the 
femur and genu combined and usually has a 
process on the inner margin, or only spines 
or small hairs may be present distally. The 
coxal plates are more or less united into one 
group. The genital indentation reaches to the 
posterior end of coxal plates i. Swimming 
hairs may or may not be present on the legs. 
Usually found in the indentation formed by 
coxal plates iv the genital organ has three to 
five pairs of genital suckers. 



Mideopsinae Koenike, 1910 

Genera and subgenera: 

1. M/V/^op^/i' Neumann, 1880 

a. Mideopsis s. str. 

Type. Hydrachua orbicularis MLiller, 1776 (= Mideopsis depressa 
Neumann, 1880) 

b. Neoxystonotiis Lundblad, 1927 
Type. Mideopsis torrei Marshall, 1927 

c. Octomideopsis Vieis, 1931 

Type. Mideopsis minutus Soar, 1910 

d. Paraxystonotusl.undh\2id, 1936 

Type. Xystonotiis willmanni Viets, 1920 

e. Xystonotiis Wolcott, 1900 

Type. Xystonotiis asper Wolcott, 1900 

2. Notomideopsis Wolcott, 1905 

Type. Mideopsis spinipes Nordenskiold, 1904 



Djeboinae Viets, 1935 
Genus and subgenera: 
Djeboa Viets, 1911 
a. Djeboa s. str. 

Type. Djeboa nudtidentata Viets, 1911 



Hydrachnellae 



315 



Djeboella ViQts, 1935 

Type, Djeboella elongata Viets, 1935 



Momoniinae Viets, 1926 



Genera: 



1. Momonia Halbert, 1906 (= Kondia Sokolow, 
Type. Momonia falcipalpis Halbert, 1906 

2. Momoniella Viets, 1929 

Type. Momoniella sumatrensis Viets, 1929 



926) 



Mideopsellinae Lundblad, 1937 



Genus: 



Mideopsella Lundblad, 1937 

Type. Mideopsella forcipalpis Lundblad, 1937 



Acalyptonotidae Walter, 1911 

Figure 247 



Diagnosis: The body of these 
mites is unarmored dorsally and 
has no dorsal suture. The palpal 
tibia is distally, dorso-ventrally 
broadened; the distal inner edge 
is elongated and forms a shear 
with the palpal tarsus. The me- 
dian suture of the anterior coxal 
plate group is lacking; the rear 
group of coxae forms an indenta- 
tion into which the genital organ 
fits. There are many suckers on 
the genital organ. 




Figure 247 Acalyptonotiis violaceiis 
Walter. Venter of female. (After 
Walter 1911) 



Genus: 



Acalyptonotus Wsiiter, 1911 

Type. Acalyptonotus violaceus Walter, 1911 



316 



Acarology 



A-Thienemanniidae Lundblad, 1930 



Figure 248 




Figure 248 Plaumannia crenophila 
Lundblad. Venter of female. (After 
Lundblad 1936) 



Diagnosis: These mites have an 
armored body and a dorsal su- 
ture. The maxillary organ usually 
has a short rostrum and the palpal 
tibia projects ventrally and distal- 
ly to form a weak shear with the 
palpal tarsus. The coxal plates 
have a tendency to grow together. 
Usually the genital organ lies in 
the opening in the ventral armor. 
As a rule genital pads are covered 
with setae and many genital suck- 
ers are present. 



A-Thienemanniinae Viets, 1923 



Genus: 



A-Thienemannia Viets, 1923 

Type. A-Thienemannia schermeri Viets, 1923 

Harpagopalpinae Viets, 1924 

Genus: 

Harpagopalpus octoporus Viets, 1924 

Mundamellinae Viets, 1931 

Genera: 

1. Mundamella Viets, 1913 

Type. Mundamella germanica Viets, 1913 

2. Hungarohydracarus Motas and Tanaschi, 1 947 

Type. Hungarohydracarus suhterraneus Motas and Tanaschi, 1947 

3. StygohydracarusWiQis, \9'i\ 

Type. Stygohydracarus troglobius Viets, 1931 

Plaumanniinae Lundblad, 1936 
Genus: 

Plaumannia Lundblad, 1936 

Type. Plaumannia arrenuripalpis Lundblad, 1936 



Hydrachnellae 



317 



Eupatrellidae Viets, 1935 

Figures 249, 250 

Diagnosis: This family is based on a nymphal form and no diagnosis 
is given here. 





Figure 249 Eiipatrella reticulata 
Walter. Palpus of nymph. (After Wal- 
ter 1935) 



Figure 250 Eupatrella reticulata Wal- 
ter. Nymph. (After Walter 1935) 



Genus: 



Eupatrella Walter, 1935 
Type. Eupatrella reticulata Walter, 
incertus Koenike, 1893) 



1935 (probably = Hydryphantes 



Arrenuridae Thor, 1900 

Figure 251 

Diagnosis: The body is armored and usually 
has a dorsal suture. On the palpus is a shear 
formed by the tibia and tarsus. The coxal plates 
are united with the ventral shield. The genital 
organ is in the opening in the ventral shield. 
Genital suckers are numerous, small and pore- 
like, and more or less growing out of plates. 
Often the male has an extension on the posterior 
of the body. Also the genu of leg iv is sexually 
differentiated. 



Figure 251 Arrenurus valencius Marshall. Dorsum of 
male. (After Lundblad 1935) 




318 Acarology 

Genera and subgenera: 

1. Arrenunis Duges, 1833 

a. Arrenunis s. str. (= Petiolurus Thon, 1900") 
Type. Arrenunis viridis Duges, 1834 

b. Megaluracarus Wiets, 1911 

Type. Hydrachnci globator Miiller, 1776 

c. M icruracarus Vieis, 1911 

Type. Arrheniinis forpicatus Neumann, 1880 

d. Micruracaropsis Viets, 1939 

Type. Micruracaropsis phytotelmaticola Viets, 1939 

e. Truncaturus Thor, 1 900 

Type. Arrenurus knauthei Koenike, 1895 

2. Africasia Viets, 1931 

Type. Mundamella arrhenuripalpis Viets, 1913 

3. DadayelkiY^OQmkQ, \901 

Type. Arrhenurella minima Daday, 1905 

4. Rhinophoracarus Wiets, 1916 

Type. Rhinophoracarus praeacutus Viets, 1916 

5. Thoracophoracarus Viets, 1914 

Type. Thoracophoracarus arrhenuroides Viets, 1914 

6. WuriaMxQXs, 1916 

Type. Wuria falciseta Viets, 1916 

7. Wuriella Viets, 1935 

Type. Wuriella sumatrensis Viets, 1935 

Krendowskiidae Lundblad, 1930 

Figures 252, 253 

Diagnosis: Body armored, with dorsal suture, paired lateral eyes in 
capsules, skin with papillae; short rostrum; palpal tarsus forms a shear. 
Coxal plates with a tendency to fuse. With immovable genital plates 
and three to eight pairs of inner genital suckers the genital organ lies 
in the indentation formed by coxae iv. 

Genera and subgenera: 
1. Kr endow skiaViers'ig, 1895 

a. Krendowskia s. str. (= Arrhenurella Ribaga, 1902) 
Type. Krendowskia latissima Piersig, 1895 

b. Krendowskiella Viets, 1931 

Type. Krendowskia megalopsis Lundblad, 1930 

c. Neokrendowskia Lundblad, 1941 

Type. Krendowskia (Neokrendowskia) quadripustulata Lundblad, 
1941 



Hydrachnellae 



319 



2. AUokrendowskia Lundblad, 1941 

Type. AUokrendowskia dentipes Lundblad, 1941 

3. GeayiaThoY, 1897 

a. Geayia s. str. 

Type. Geayia venezuelae Thor, 1897 

b. Ger/y£^//« Lundblad, 1936 

Type. Geayia {Geayella) catharinensis hundb\3.d, 1936 

c. Geayidea Lundblad, 1941 

Type. Geayia coeruleocruciata Lundblad, 1 936 

d. Pirapama Viets, 1935 

Type. Pirapama schubarti Viets, 1935 





Figure 252 Krendowskia megalopsis Figure 253 Krendowskia megalopsis 
Lundblad. Dorsum of female. (After Lundblad. Venter of female. (After 
Lundblad 1930) Lundblad 1930) 



4. RoqueellaUindh\did,\9?>0 

a. Roqueella s. str. 

Type. Roqueella flabellifera Lundblad, 1930 

b. Neoroqueella Lundblad, 1937 

Type. Roqueella (Neoroqueella) maculata Lundblad, 1937 

c. Pararoqueella Lundblad, 1937 

Type. Roqueella {Pararoqueella) striata Lundblad, 1937 



CHAPTER VII 



The Suhordei^ Sarcoptifoimes Renter^ 1909 



STIGMATA are not present but some possess a tracheal system 
opening through porose areas on various parts of the body. The 
coxae form apodemes beneath the skin on the venter of the body. The 
cheUcerae are usually scissors-like, for chewing, with strong chelae; a 
few have specialized or modified chelicerae. The palpi are simple. 
Pseudostigmatic organs may or may not be present. Anal suckers are 
often present in the male. 

The Sarcoptiformes are divided into the Acaridiae and the Oribatei, 
the former containing the cheese mites, itch mites, and feather mites, 
and the latter the oribatid mites. Although the two groups can be sepa- 
rated rather easily, their relationship is close and they possess many 
characters in common, such as body shape in many of the genera, 
mouth parts for chewing, arrangement of coxal plates, and the Clapa- 
rede organ which is to be found in larvae of both groups. 

Key to the Sarcoptiformes 

1. Weak skinned, nonarmored; without pseudostigmata and promi- 
nent clublike pseudostigmatic organs (exception: Pediculocheli- 
dae); tarsi with caruncles; sexual dimorphism at times strongly 
marked; many males with copulatory suckers on tarsi or anal 
region Acaridiae 

Leather-like or strongly sclerotized; usually, with only a few ex- 
ceptions, with prominent clublike pseudostigmatic organs; tarsi 
without caruncles; sexual dimorphism not marked Oribatei 

ACARIDIAE LATREILLE, 1802 

The gnathosoma is usually visible from above, rarely being con- 
cealed within a camerostome. No stigmata or tracheae are to be found. 

320 



Sarcoptiformes 32 1 

Pseudostigmatic organs are not present. The body is, as a rule, soft 
skinned but usually has a dorsal plate or plates. The coxae form char- 
acteristic plates. The tarsi usually have a stalked or sessile empodial 
claw and caruncle, and when without claws the caruncle is bell-like. 
The palpi are simple, usually with two free, seldom four, movable 
segments. Sexual dimorphism is marked in some cases. Two pairs of 
genital suckers are usually present, and the males generally have prom- 
inent adanal suckers. 

The Acaridiae can be divided into the free-living type (Acaridae or 
cheese mites), the parasitic type (Sarcoptes or itch mites), and the 
feather- or hair-inhabiting type (feather mites) and by certain mor- 
phological structures such as skin sclerotization and striations, but 
actually there are not clear-cut morphological differences to be found 
here as in the other suborders. 



Key to the Acaridiae 

1. Body without plates, or with single, lightly sclerotized propodo- 
somal shield (occasionally hysterosomal shield present); legs not 
modified for clasping hairs; as a whole, free-living mites or skin 
parasites 2 

Body plates strongly sclerotized, usually with more than one well- 
defined shield; or legs or maxillae modified for clasping hairs; 
feather or hair mites 27 

2. Hysterosoma not segmented 3 

Hysterosoma divided into four sections by transverse sutures; 
propodosoma with pair of bladder-like sensory setae; tarsi with 
caruncles but no claws Pediculochelidae 

3. Chelicerae with opposed chelae, although sometimes minute 4 
Fixed chela reduced, movable chela normally developed 17 

4. Caruncle with claws, sometimes very minute (Ensliniellidae and 
Canestriniidae ^) 5 

Caruncle without claws 19 

5. Caruncle sessile and with claw 6 

Caruncle more or less pedunculate, on distal part of which is 
claw, often minute 8 

1 After Vitzthum; Canestriniidae fits in very close to Sarcoptidae; in some cases the 
claws seem to have disappeared; with different type of caruncles on tarsi. 



322 Acarology 

6. Males with copulatory suckers on tarsi iv and near anal plate 
(exception: Caloglyphus anomalus Nesbitt) 7 

Males without copulatory suckers on tarsi or near anal plate; 
larvae without "urstigma"; genital opening between coxae iv 

Saproglyphidae 

7. Body setae of adults long, loose, whiplike; in young stages often 
stiff, rodlike Acaridae 

Body setae of adults feathered, pectinate, clublike Forcelliniidae 

8. Skin smooth, fine, not sclerotized 9 
Skin sclerotized, leathery, scaly, not smooth 15 

9. Caruncles terminal on all legs 10 

Caruncles of legs i and ii which bear terminal claws long, cylin- 
drical, and flexible and placed laterally on clawlike tarsus; tarsi 
III and IV normal Hyadesidae 

10. Body with suture between propodosoma and hysterosoma 11 

Body without suture; no propodosomal shield; dorsal body setae 
simple, with two pairs of long posterior setae; epimera of legs 
I and II united and partially encompassing female genital opening 
which lies between legs ii and in Carpoglyphidae 

11. Without cervical setae; without suckers on tarsus iv or near anal 
opening in male 12 

With cervical setae; males with suckers on tarsi iv or near anal 
opening 14 

12. No lenslike eyes present in place of cervical setae 13 

Lenslike eye in place of each cervical seta; no propodosomal 
shield; body with four pairs of long, whiplike setae, two pairs on 
rear, one on shoulders of hysterosoma and one pair in posterior 
row of propodosomal setae; genital opening of female between 
coxae III and iv; male not known Oulenziidae 

13. Female genital opening between coxae iii; male genital opening 
between coxae iv; dorsal setae simple, of medium length; with 
propodosomal shield Ensliniellidae 

Female genital opening between coxae iii and iv; with propo- 
dosomal shield; dorsal body setae as a whole, short; dorsal sur- 
face of body very finely wrinkled Czenspinskiidae 

Female genital opening between coxae iv; with propodosomal 
shield; dorsal setae simple, of medium length Winterschmidtiidae 



Sarcoptiformes 323 

14. Cervical setae marginal, long, pilose; female genital opening be- 
tween coxae in; male genital opening between coxae iv; tarsal 
claws in larvae and nymphs single, normal; in adults claws dou- 
ble, Y-shaped or forked on tarsi i and ii Lardoglyphidae 

Cervical setae marginal, minute, almost a curved spine; tarsi i-iii 
each with three spoon-shaped or lanceolate setae; tarsus iv with 
one such seta; tarsal claws with a ventral knob; body with three 
pairs of long setae; adults not known, described from nymph 

Olafseniidae 

15. Male genital opening between coxae iii-iv 16 

Male genital opening between coxae i-ii; male with tarsal iv and 
anal suckers; body acarid-like, but skin well sclerotized; dorsal 
setae simple, very short; female genital opening between coxae 
iii-iv Chortoglyphidae 

16. Skin dull, or roughened by numerous fine distinct points or scales; 
body variously shaped; tarsi gradually tapering towards tip, with 
caruncle, on distal half of which is claw, often minute; clublike 
sensory setae on tarsi i and ii; dorsal setae usually pilose, feath- 
ered, or fanlike Glycyphagidae 

Skin leathery or scaly; body depressed, round or oval, lozenge- 
shaped or almost quadrangular; tarsi with pedunculate caruncle; 
claw, which is often minute (and apparently absent at times), 
wholly involuted in caruncle; tarsi i and ii without clublike sen- 
sory sestae; dorsal setae simple Canestriniidae 

17. Movable chela sawlike; all legs of more or less equal size and 
equally developed 18 

Movable chela not sawlike, enclosed in tube formed by palpi; legs 
I and II with claws but no lobes; legs in and iv enormously devel- 
oped into clasping organs without claws but with tarsi adapted as 
claws; found on gills of crab Ewingidae 

18. Distal segment of palpus with two flagella; caruncle with sessile 
claw Anoetidae 

Palpus with normal setae; tarsi with caruncles without claws; dis- 
tal portion of tarsus clawlike Linobiidae 

19. With pair of anterior vertical propodosomal setae 20 
Without vertical setae on propodosoma 21 

20. Skin smooth; body segmented between propodosoma and hystero- 
soma; few long, simple setae; tarsi with sessile caruncles; free- 
living mites Nanacaridae 



324 Acarology 

Skin smooth, body segmented between propodosoma and hystero- 
soma; propodosomal shield present; body setae few, tiny; tarsi 
with bell-like caruncles on long stalks; free-living mites 

Hemisarcoptidae 

Skin with strong transverse striations; body without suture be- 
tween propodosoma and hysterosoma; caruncles stalked, on short 
legs; skin parasites Sarcoptidae 

21. Mouth parts well developed, chelicerae chelate for chewing 22 

Mouth parts reduced, specialized into sucking tube; small, hair- 
less mite; tarsi with caruncles but without claws; in air sacks of 
chickens and lung tissue of squirrels Cytoditidae 

22. Legs I and ii with caruncles 23 

Legs I and ii without caruncles but tarsi divided into clawlike 
points; tarsi in and iv with caruncles; elongated mite; in subcu- 
taneous tissues of fowl Laminosioptidae 

23. Caruncle or adhesive lobes on short or long stalks; caruncle of 
normal size or even smaller, never greatly enlarged 24 

Caruncle not stalked, of monstrous size; tarsi in and iv with three 
ventral, clawlike spines pointing to rear; on skin of small birds 

Heteropsoridae 

24. Tarsi i with caruncles 25 

Tarsi i without caruncles and shaped like anchor; with propodo- 
somal shield; no suture between propodosoma and hysterosoma; 
legs on anterior portion of body; tarsi ii, in, and iv without claw 
but with adhesive lobe Myialgesidae 

25. Caruncles on all legs of females 26 

Tarsi ni of females ending in long whiplike setae; posterior margin 
of male bilobate; usually skin parasites of mammals Psoroptidae 

26. Small mites with propodosomal shield; female rounded; male 
bilobate on rear; larvae and nymphs with caruncles on all legs (?) 

Epidermoptidae 

Small mites with propodosomal shield; female rounded; male 
bilobate on rear; larvae and nymphs with caruncles on legs i 
and n only Psoralgidae 

27. Maxillae and legs normal, not modified for clasping hair 28 
Maxillae or one or more pairs of legs modified into clasping organs 
for grasping hairs of host Listrophoridac 



Sarcoptiformes 325 

28. Legs I and ii normal, segments cylindrical, without spinelike 
projections 29 

Legs I and ii with sharp latero-ventral projections on segments 

Analgesidae 

29. Rear of hysterosoma of both sexes rounded or slightly bilobate 

Dermoglyphidae 

Rear of hysterosoma of female and often of male tapering, 
strongly bilobate Proctophyliodidae 



Pediculochelidae Lavoipierre, 1946 

Figure 254 

Diagnosis: The pediculochelids are tiny, whitish mites measuring 
from 0.184 to 0.24 mm. in length. Their skin is soft, striated, and 
without plates. Separated from the propodosoma by a distinct suture, 
the hysterosoma is divided by three dorsal, transverse sutures. The 




Figure 254 Pediculochelus raidti Lavoipierre. Dorsal view of female. 

propodosoma' lacks eyes, but has several long, whiplike setae and a 
pair of dorsal clavate sensory setae. A pair of vertical setae is also 
present. The chelicerae are large and have strong, opposed chelae for 
chewing or crushing as in the oribatid mites. The palpus is four-seg- 
mented, simple, and has few setae. The legs are relatively weak and 
the tarsi lack claws but have a sucker-like caruncle on a pedicle. The 
anal opening is on the rear and there are two pairs of genital suckers. 



Genus: 



Pediculochelus Lavoipierre, 1946 

Type. Pediculochelus raulti Lavoipierre, 1946 



326 



Acarology 



Discussion: Lavoipierre 1946 found the only known species, Pedi- 
culochelus raulti Lavoipierre, associated with bees at Durban, Natal, 
South Africa; a single specimen was collected on a rat in Florida dur- 
ing an ectoparasitic survey of rats in that region, and specimens have 
been found on Gallus gallus on the island of Samar in the Philippines. 
The body is segmented and the general appearance is that of a primitive 
type of acarid-like mite which is perhaps an intermediate form between 
these and the oribatids. This would indicate a more or less general 
acarid habitat. Because of their minute size the mites have probably 
been overlooked up to the present time. 

Reference: 

Lavoipierre, M. 1946. A new acarine parasite of bees. Nature 158 (4004) : 
130, 131. 



Saproglyphidae Oudemans, 1924 

Figure 255 




Figure 255 Saproglyphus negiectus 
Berlese. Dorsal view of female. 
(After Berlese 1890) 



Diagnosis: It is possible that 
these mites do not have any pro- 
podosomal shield. Their skin is 
smooth. The propodosoma and 
hysterosoma are separated by a 
suture. A transverse row of four 
setae is situated on the rear of the 
propodosoma, the inner pair be- 
ing considerably shorter than the 
outer. A pair of vertical setae are 
also present and the marginal 
setae of the body are very long 
and whiplike. All tarsi have a 
claw and caruncle. The female 
genital opening lies between coxae 
III and IV while the male genital 
opening is between coxae iv. In 
the male there are no adanalcop- 
ulatory suckers and no suckers on 
tarsi IV. 



Sarcoptiformes 



327 



Genus: 

Sciproglyphus Berlese, 1890 

Type. Sciproglyphus neglectiis Berlese, 1890 

Discussion: Saproglyphus neglectus Berlese was collected on rotting 
shelf fungus, Poly poms hispidus, in Italy; 5. cocciphagus Womersley, 
1941 was found in gall on tree-lucerne in New South Wales, Australia. 

References: 

Berlese, A. 1890. Acari, Myriopoda et Scorpiones Crypt. Fasc. LXXXIX, 

No. 11; Fasc. LVII, No. 6. 
Womersley, H. 1941. Studies in Australian acarina (2) Tyroglyphidae 

(s.l.) Rec. South Austral. Mus. VI(4) : 451-488. 



Acaridae Ewing and Nesbitt, 1942 

(= Tyroglyphidae Donnadieu, 1868) 
Figures 256-262 

Diagnosis: ^ The body of these mites is dis- 
tinctly divided into a proterosoma and hystero- 
soma by a transverse groove. The body is stout, 
white, or fawn and the integument is usually 
smooth aAd shiny, rarely rough. The chelicerae 
are chelate. Five pairs of setae are found on the 
propodosoma: (i) rostral setae; (ii) Grand- 
jean's organ in Acarinae = nuchal setae in 
Rhizoglyphinae; (iii) cervical bristles; (iv) 
outer propodosomatic setae; (v) inner propo- 
dosomatic setae (a reduction in the number of 
these setae is to be found in the genera Thyreo- 
phagus and Histiogaster) . Usually the anterior 
part of the propodosoma is covered by a shield. 
In all genera a pseudostigmatic org^ is present. 
The male and female genital opening is between 
coxae III and iv. Two distinct copulatory suckers are located on either 
side of the male anus. Epimera i is united to the sternum but all others 
are free. All coxae except iv bear a spine on the ventral surface. The 
tarsi may be longer than the tibia plus the genu. Tarsus i bears: (i) 
macrosense seta with a microsense seta before it at its base; (ii) sub- 

1 After Nesbitt 1945. 




Figure 256 Rhizogly- 
phus echinopus (Fu- 
mouze and Robin). 
Ventral view of larva. 
Note Claparede's 
organ or iirstigma 
on coxa i. 





Figure 257 Rhizoglyphiis echinopus 
(Fumouze and Robin). Ventral view 
of protonymph. 



Figure 258 Rhizoglyphiis echinopus 
(Fumouze and Robin). Ventral view 
of hypopus. 





Figure 259 Rhizoglyphiis echinopus Figure 260 Rhizoglyphiis echinopus 
(Fumouze and Robin). Ventral view (Fumouze and Robin). Ventral view 
of deutonymph. of male. 

328 



Sarcoptiformes 329 

basal seta with the occasional addition of a parasub-basal seta; (iii) a 
group of four median setae; (iv) a ventral-terminal group of three to 
five spines; (v) a dorsal-terminal group of four long setae that may be 
modified; (vi) a claw surrounded by a caruncle that is never pedun- 
culate. Tarsus ii bears a macrosense seta but does not have either a 
microsense seta or a parasub-basal seta. Tarsus in in heteromorphic 




r^^ASM 





Figure 261 Rhizoglyphus echinopiis 
(Fumouze and Robin). Ventral view 
of heteromorphic male. 



Figure 262 Rhizoglyphus echinopus 
(Fumouze and Robin). Ventral view 
of gravid female. 



males is modified as a large claw. Tarsus iv in the female bears two lat- 
eral spines; in the male these are replaced by two suckers, except in the 
genus Thyreophagus where there is only one. In the more primitive 
members of the group the tarsal setae are thin, slight hairs; in the more 
advanced members they become modified as large spines. Larvae have a 
well-developed, cylindrical, or pin-shaped "Bruststiele" (urstigmata). 

Key to the Acaridae 

1. Without sexual dimorphism; inner propodosomal setae as long as 
or longer than outer; legs slender with hairlike setae, lateral and 
mesial median setae of tarsi unmodified; microsense and macro- 
sense setae not arising from same base Acarinae 



330 Acarology 

Frequently with well-developed sexual dimorphism; inner propo- 
dosomal setae shorter than outer; legs stout, the setae in many 
cases being modified as stout spines; microsense and macrosense 
setae arising from same base Rhizoglyphinae 

Nesbitt 1950 has placed the Pontoppidanidae as a subfamily of the 
Acaridae and separates them thus: 

Nuchal setae thin, rootlike structures adhering closely against the 
lateral wall of the body Acarinae 

Nuchal setae distinct hornlike processes standing free of body 

Rhizoglyphinae 

Nuchal setae distinct, heavily pectinated processes standing free 
of body and readily visible in dorsal mounts Pontoppidaniinae 

Acarinae Nesbitt, 1945 

Genera and subgenera: 

1. ^c«ri^5 Linnaeus, 1758 (= T>^ro^/);/7/iM5 Latreille, 1796) 
Type. Accirus siro Linnaeus, 1758 

2. Aleuroglyphus Zakhvatkin, 1940 

Type. Tyroglyphus ovatus Troupeau, 1879 

3. Ebertia Oudemans, 1924 

Type. Tyroglyphus australis Oudemans, 1917 

4. Podoglyphus Oudemans, 1937 

Type. Glyciphagiis biiski Murray, 1877 

5. Tyrolichus Oudemans, 1924 

Type. Tyrolichus ccisei Oudemans, 1910 

6. Tyrophagus Oudemans, 1924 {— Coelognathus v. Heffling, 1852) 

a. Tyrophagus s. str. 

Type. Acarus putrescentiae Schrank, 1781 

b. Tyroborus Oudemans, 1924 

Type. Tyroborus lini Oudemans, 1924 

c. Povelsenia Oudemans, 1924 

Type. Tyroglyphus neotropicus Oudemans, 1917 

Rhizoglyphinae Zakhvatkin, 1941 

Genera and subgenera: 

1. Rhizoglyphus Claparede, 1869 

Type. Tyroglyphus echinopus Fumouze and Robin, 1868 

2. Caloglyphus Berlese, 1923 (? = AcJiropodophorus Rosas Costa, 

1927) 
Subgenera of Caloglyphus after Vitzthum 



Sarcoptiformes 331 

a. Caloglyphus s. str. 

Type. Tyroglyphiis berlesei Michael, 1903 (= Tyroglyphus myco- 
phagus Berlese, 1891, sed non Megnin, 1874) 

b. Pachyglyphus Berlese, 1923 

Type. Tyroglyphus pergandis Berlese, 1920 

c. Lagenoglyphus Berlese, 1923 

Type. Tyroglyphus lamermanni Berlese, 1923? 

d. Isoglyphus Zakhvatkin, 1937 

Type. Isoglyphus sphaerogoster Zakhvatkin, 1937 

3. Ceroglyphus Vitzthum, 1919 (= Petzschia Oudemans, 1923) 
Type. Ceroglyphus monstruosus Vitzthum, 1919 

4. Eherhardia Oudemans, 1924 (= Acotyledon Oudemans, 1903) 

a. Eherhardia s. str. 

Type. Eherhardia michaeli Oudemans, 1924 (= Rhizoglyphus 
agilis Michael, 1903) 

b. Cosmoglyphus Oudemans, 1932 

Type. Tyroglyphus kramerii Berlese, 1881 

5. Froriepia Vitzthum, 1919 — deutonymph 
Type. Froriepia vimariensis Vitzthum, 1919 

6. Garsaultia Oudemans, 1916 — deutonymph 
Type. Garsaultia testudo Oudemans, 1916 

7. Histiogaster Berlese, 1883 

Type. Tyroglyphus carpio Kramer, 1882 

8. Megninietta Jacot, 1936 

Type. Megninietta ulmi Jacot, 1936 

9. Mycetoglyphus Oudemans, 1932 

Type. Mycetoglyphus fungivorus Oudemans, 1932 

10. Myrmoglyphus Vitzthum, 1935 — deutonymph 
Type. Myrmoglyphus bipilis Vitzthum, 1935 

11. Sancassania Oudemans, 1916 — deutonymph 
Type. Sancassania chelone Oudemans, 1916 

12. Schwiebea Oudemans, 1916 

Type. Schwiebea talpa Oudemans, 1916 

13. Stereoglyphus Berlese, 1923 

Type. Stereoglyphus haemisphaericus Berlese, 1923 

14. Suidasia Oudemans, 1905 (= Aphelenia Oudemans, 1923) 
Type. Suidasia pontifica Oudemans, 1905 

(Nesbitt did not place this genus in with the Acaridae but left 
it dangling; however, it is placed here following Vitzthum's 
list.) 

15. Thyreophagus Rondani, 1874 (= Monieziella Berlese, 1897) 
Type. Acarus entomophagus Laboulbene, 1852 

16. Tyroglyphopsis Vitzthum, 1926 — deutonymph 
Type. Tyroglyphopsis ocellata Vitzthum, 1926 



332 Acarology 

17. Valinontia Oudemans, 1923 

Type. Valinontia niira Oudemans, 1923 

18. Viedebanttia Oudemans, 1929 — deutonymph 
Type. Viedebanttia schniitzi Oudem'dns, 1929 

Pontoppidaniinae Oudemans, 1925 

Genera: 

1. Pontoppidania Oudemans, 1923 

Type. Tyroglyphiis littoralis Halbert, 1920 

2. Ca/vo//a Oudemans, 1911 

Type. Calvolia hagensis Oudemans, 1911 (= Tyroglyphiis heteroco- 
mils Michael, 1913, hypopus) 

3. Diphtherogly phus l<lesbin, 1950 

Type. Diphtherogly phus maculata Nesbitt, 1950 

Discussion: 

the members of the family Acaridae are notable for the extent of their 
distribution. They are found in all types of habitat from Arctic tundra to 
tropical rain forests and wherever man in his wanderings has taken mites in 
his food and produce. Living on all kinds of organic substances, these crea- 
tures are commonly found infesting such materials as preserved meats, 
cured and raw hides, organic powders, seeds, and farinaceous products. In 
stored grains they cause great economic loss not so much by what they eat 
(although populations of astronomical figures are found at times) as by the 
damage that they cause by changing the moisture content of the medium 
and initiating the growth of moulds. In the state of nature they are usually 
found on rotting leaves and plant debris, on the bark of trees, on decaying 
bulbs and tubers, on fresh and putrid mushrooms, and in the nests of mam- 
mals and birds, where presumably they live on organic wastes and bits of 
hair and feathers. In speaking of ecological niches it is interesting to note 
that, even as the family may be divided taxonomically into two quite dis- 
tinct subfamilies on morphological grounds, it may also be separated into 
the same two subfamilies on the basis of the type of habitat preferred. 
Almost without exception the members of the one group prefer to live in 
substances having a low moisture content (20 to 30 per cent), viz., wheat, 
seeds, and stored farinaceous products, whereas the members of the other 
group can exist only in a very humid habitat, many seeming to prefer a 
place where they are wading in a film of water. As a result of these studies, 
I am persuaded that the members of the former group can, and do, eat the 
more solid organic substances such as the germ and endosperm of seeds, 
whilst those of the latter group live fairly exclusively on the fungi and 
moulds growing on the excessively damp substratum that they prefer. Fur- 



Sarcoptiformes 333 

thermore, many eat dead and decaying insects, the caloglyphids being the 
most notable example. Apart from a few species of the genus Thyreopha- 
giis, which live on oyster-shell scale and kindred insects, none of the family 
appears to be either a predator or a parasite. As yet no fossil records have 
been found of either the Acaridae or their immediate progenitors, but this 
is not to be wondered at, as they are extremely small creatures, which do 
not lend themselves to easy fossilization.^ 

The life cycle of the mite may be summarized briefly as follows, 
Rhizoglyphus echinopus (Fumouze and Robin) being used as an ex- 
ample. Garman 1937 found that at a room temperature of 60°-75° F. 
(68° average) the mite went through its life cycle in seventeen to 
twenty-seven days; and that at 70°-80° F. its life cycle was completed 
in nine to thirteen days. The mite becomes torpid at 55°-50° in the 
lower temperature range and at about 95° in the upper extreme. The 
mite needs a rather high humidity. Garman Hsts the stages as follows 
(between each stage, except egg and larva, the mite becomes quies- 
cent). 

A. Cycle in which the hypopial stage (second nymph) is omitted 
Egg — larva — first nymph — third nymph 

adult female 
normal male 
heteromorphic male 

B. Cycle with hypopial stage (second nymph) 

Egg — larva — first nymph — hypopus — third nymph 
adult female 
normal male 
heteromorphic male 

Many of the Acaridae have a hypopial or "wandernymph" stage in 
which the mite changes into a small creature with suckers or claspers 
for grasping insects for dispersal, and at times they have been mistaken 
for parasites. Apparently the mites can withstand dryness best in this 
stage. The hypopus of one species ha^ even been taken from the gill 
chambers of a moUusk and another from the gonads of a millipede. 
Whereas the length of the hypopal stage is from five to thirteen days, 
the other stages are from three to eight days or less. The hypopi then 
develop into nymphs which may produce any type of adult. Michael 
1901 found hypopi of various acarids produced under several condi- 
tions and could describe no reason for their development. Garman 

1 FromNesbitt 1945. 



334 A carology 

1937, on the other hand, found that Rhizoglyphus echinopus (Fu- 
mouze and Robin) produced most hypopi under wet, sticky conditions. 
This has also been observed in species of Histiostoma and Calogly- 
phiis. 

The heteromorphic male is to be found in various genera of the 
Acaridae, and that of Rhizoglyphus echinopus is shown in Figure 261. 
With some species it is rarely found, but with R. echinopus as high as 
20 per cent of the males may be heteromorphic. They may be easily 
distinguished by the enlarged third pair of legs. These males breed 
with the females and produce both types of males as well as females. 
The normal male, mated with a female, will also produce the same 
type of offspring. 

Rhizoglyphus echinopus (Fumouze and Robin), the well-known 
bulb mite, is cosmopolitan in distribution and may be found in bulbs 
of amaryllis, crocus, Easter lily, gladiola, hyacinth, narcissus, and tu- 
lip. It can probably feed on most tubers, especially those which have 
loose scales permitting the entry of the mite. Shipments are usually 
infested with this mite, which may destroy as high as 15 to 20 per cent 
of the bulbs. However, the rotted area is not always due to the mite 
but can be caused by other factors. In the field the mite apparently 
does little damage to healthy plants, affecting only rotted bulbs, but 
if the mites become established in stored bulbs they appear to hasten 
decay. Although it usually feeds on rotted or decayed tissue the mite 
can infest healthy tissue if in contact with it. This indicates the neces- 
sity of eliminating rotten, infested bulbs to prevent the spread of the 
mite in storehouses. The mites probably carry fungus and bacterial 
diseases with them externally. 

Tyrophagus lintneri (Osborne)^ is a widely distributed pest, seri- 
ous in stored foods, and at one time on cultivated mushrooms. The 
mites eat the spawn and make holes in the stems and caps of the 
mushrooms and can seriously hinder mushroom culture if not con- 
trolled (Davis 1944). It is to be found in greasy soda fountains and 
in cupboards wherever food is available. 

Thyreophagus entomophagus Laboulbene has been found associated 
with dried insects in collections and with scale insects in the field. Al- 
though occasionally reported as being predaceous on the scale insects 
they actually live on the cast skins and dead scales, which must be 
slightly moist. In brief, it can be said that this mite lives on dried ani- 

1 Caloglyphus sp. has displaced Tyrophagus lintneri in mushroom houses in Mary- 
land and Pennsylvania withn the last few years. 



Sarcoptiformes 335 

mal and vegetable matter. It appears to be cosmopolitan in distribution. 

Acariis siro Linneaus is a destructive cosmopolitan species found in 
grain and flour, as well as in cheese, dried fruits, and vegetables. The 
mite actually eats the grain, leaving only the husk. The male is easily 
distinguished by a large, toothlike projection on femur i. 

Tyrophagiis longior (Gervais) is another well-known European 
species and has been taken occasionally in America. Michael 1903 says 
that an entire haystack in Ireland was practically destroyed by these 
mites, and at times countless millions of them may be on hay and 
fodder. It also infests foodstuffs. This mite has been found in human 
feces, and their presence in the intestinal tract causes pain, nausea, 
vomiting, and diarrhea. The mites are finally passed. The patient must 
have a constant supply of mites on food or the symptoms disappear. 
Oviposition and hatching take place in the intestine but the comple- 
tion of the life cycle is doubtful. Hinman and Kampmeier 1934 also 
report cases from literature of infestation of the urogenital system, 
probably from contaminated catheters. 

Van den Bruel 1940 reports Tyrophagus dimidiatus (Hermann) 
injuring spinach in unheated greenhouses in Belgium. The value of 
the crop was reduced 80 per cent. Blades of the inner leaves were very 
short, crumpled, and deformed. The petioles were normal. The epi- 
dermis was at times perforated with small holes surrounded by a corky 
tissue. The leaves finally turned black. The damage was attributed 
to this mite which was present in large numbers and was brought in 
on manure. Similar damage has been reported from spinach fields in 
the eastern United States, the same mite species being present. 

Tyrophagus castellanii (Hirst) causes the "copra itch" of handlers 
of that product. Sigrianskii 1940 also reports Tyrophagus castellanii 
(Hirst) as feeding on spores of Tilletia tritici and transmitting these 
spores to healthy wheat on their body and hairs. Mites that fed on 
onions infected with Botrytis allii transmitted the spores to healthy 
onions. They were also able to transmit a virus disease from infected 
to healthy potatoes. 

A mite, Caloglyphus julidicolus Lawrence (hypopus), was taken on 
the gonads of a South African millipede and is found only on the 
males. Lawrence 1939 states that it must have entered through "the 
narrow opening between the apices of the gonopods and their sur- 
rounding membranous sheath, passing upward and slightly forward 
for a distance of about 5 mm. before arriving at the final place of 
attachment to the bases of the gonopods. The mites appear to have 



336 Acarology 

sought out the most sheltered parts of the sex organs of the host." 
Halbert 1920 gives the following information on Pontoppidania 
littoralis (Halbert): 'Two females and a male found in moist decay- 
ing seaweed amongst shingle close to the harbour at Howth, Co. 
Dublin. The locality is slightly above high-water mark, and evidently 
within reach of high tides, September, 1918." Calvolia hagensis Oude- 
mans hypopus is pecuhar in that it possesses a pair of large, lenslike 
eyes near the anterior end of the body. Diphtheroglyphus maculata 
Nesbitt were taken from salted steer hides, Buenos Aires, Argentina. 

References: 

Andre, M. 1931. Acariens nuisables aux produits pharmaceutiques. Assoc. 
Fran? pour I'Avanc. des Sci., pp. 395-399. 

. 1935. Acariens infestant les milieux de culture dans les laboratoires. 

Assoc. Frang pour TAvanc. des Sci., pp. 469-471. 

Davis, A. C. 1944. The mushroom mite [Tyrophagus lintneri (Osborne)] 

as a pest of cultivated mushrooms. U. S. Dept. Agr. Tech. Bull. 879. 

V/Ewing, H. E., and H. H. J. Nesbitt. 1942. Some notes on the taxonomy of 

grain mites (Acarina: Acaridae, formerly Tyroglyphidae). Proc. Biol. 

Soc. Wash. 55: 121-124. 

^ Grandjean, F. 1937. Sur quelques caracteres des Acaridiae libres. Bull. 

Soc. Zool. France. 62 (6) : 388-398. 
v^ Halbert, J. N. 1920. The Acarina of the seashore. Proc. Roy. Irish Acad., 
35, Sect. B, No. 7: 106-152, Pis. 21-23. 
Hinman, E. H., and R. H. Kampmeier. 1934. Intestinal Acariasis due to 
Tyroglyphus longior Gervais. Amer. J. Trop. Med. 14 (4) : 355-362. 
Hughes, A. M. 1948. The mites associated with stored food products. Min- 
istry of Agriculture and Fisheries, London, pp. 1-168. 
\/ Nesbitt, H. H. J. 1945. A revision of the family Acaridae (Tyroglyphidae), 
order Acari, based on comparative morphological studies. Canad. J. 
Res., D, 23: 139-188. 

^ . 1950. On a new Argentinian mite, Diphtheroglyphus maculata n. 

sp., n. gen., and the taxonomic position of the family Pontoppidanidae 
Oudms. 1925. Can. Ent. 82 (10): 211-216. 
Snyder, W. C, and H. N. Hansen. 1946. Control of culture mites by ciga- 
rette paper barriers. Mycologia 38 (4) : 455-462. 
Solomon, M. E. 1943. Tyroglyphid mites in stored products. 1. A survey 
of published information. Dept. of Scientific and Industrial Research. 
London, pp. 1-36. 

. 1944. Tyroglyphid mites in stored products. 1. A survey of published 

information. Supplement, 1944. Dept. of Scientific and Industrial 
Research. London, pp. 1-7. 



Sarcoptiformes 



337 



. 1945. Tyroglyphid mites in stored products. Methods for the study 

of population density. Ann. Appl. Biol. 32 (l):71-75. 

. 1946. Tyroglyphid mites in stored products. Nature and amount of 

damage to wheal. Ann. Appl. Biol. 33 (3): 280-289. 

. 1946. Tyroglyphid mites in stored products. Ecological Studies. Ann. 

Appl. Biol. 33 (1): 82-97. 

Van den Bruel, W. E. 1940. Un ravageur de Fepinard d'hiver: Tyro-^ 
glyphus dimidiatiis Herm. {longior Gerv.). Bull. Jnst. Agron. Gem- 
bloux 9 (1-4): 81-99. 

Zakhvatkin, A. A. 1940. Key to mites injuring stores of agricultural prod- 
ucts in U.S.S.R. (in Russian). Uchenye Zapiski Mosk. Godudarst 
Univ. No. 42, 2 Vol., pp. 7-68. 



Forcelliniidae Oudemans, 1927 

Figures 263, 264 



Diagnosis: These mites have a 
propodosomal shield and a shiny, 
smooth (?) skin. On the posterior 
part of the propodosoma is a 
transverse row of four setae, the 
inner pair being somewhat shorter 
than the outer. The body setae 
are mostly rodlike or narrow, 
clubhke, and feathered. Cervical 
setae are dorsal, feathered, comb- 
like, and placed in a line with 
trochanter i. A pair of vertical 
setae are also present. The female 
genital opening lies between coxae 
III and IV while the male genital 
opening is between coxae iv. The 
male has adanal copulatory suck- 
ers and two suckers on tarsi iv. 
They have not been found since 
the original descriptions and con- 
sequently detailed knowledge of 
their structure is not known. 




Figure 263 ForceUinia wasmanni 
(Moniez). Dorsal view of female. 
(After Michael 1903) 



338 
Genera: 

1 



Acarology 



Forcellinia Oudemans, 1924 
Type. Tyroglyphus wosmanni Moniez, 1892 
2. Scatoglyphiis Berlese, 1913 

Type. Scatoglyphiis polytrematiis Berlese, 1913 

Discussion: Forcellinia wasmanni (Moniez) was described from ants' 
nests and is European in distribution. All stages of the mite are to be 
found in the nests. According to information from Michael 1903 the 
mites often appear to increase in great numbers in nests and the hypopi 
adhere to the ants in such quantities that they cause the death of the 
ant. Fifty to a thousand mites may be found attached to one ant. They 




Figure 264 Forcellinia wasmanni 
(Moniez). Dorsal view of nymph. 
(After Michael 1903) 



are most numerous on the head, abdomen, and legs; only a few are 
found on the thorax. The hypopi are supposed to attach themselves 
in the direction of the long axis of the segment they are on, their an- 
terior end being directed toward the point of the segment. 

Scatoglyphiis polytrematus Berlese was found in fowl excrement 
with other acarids. 



Rejerences: 

Berlese, A. 1913. Acari Nuovi. Redia 9: 77-105. 
Michael, A. D. 1903. British Tyroglyphidae 2: 131-136. 



Sarcoptiformes 339 

Hyadesidae Halbert, 1915 

Figures 265, 266 

Diagnosis: Strongly arched dorsally the body of these mites is plump. 
The propodosoma and hysterosoma are separated by a suture. A pair 
of vertical setae are present and a delicate propodosomal shield may 
also be present. The skin is otherwise soft, with very fine striae. The 
chelicerae are normal. Tarsi i and ii in both sexes are in shape of a 
large claw, with an accessory claw on the inside; the extremely long 




Figure 265 Hyadesia algivo- Figure 266 Left, leg i of Hyadesia algivorans 

rans (Michael). Dorsal view (Michael). (After Michael 1901); right, leg i 

of female. (After Michael of //yaa'e^/fl ///.?cfl Lohman. (After Andre 1931) 
1901) 

Stalk of the small caruncle, which carries distally the very small, true 
claw, is attached at the base of the accessory claw. Tarsi iii and iv of 
the female have one large claw on a short stalk; in the male the large 
claw sits on a longer stalk. There is slight sexual dimorphism. Both 
male and female genital openings are at a considerable distance be- 
hind coxae IV. There are no genital suckers nor does the male have 
adanal copulatory suckers. 

Genus: 

Hyadesia Megnin, 1889 (= Lentungula Michael, 1893) 
Type. Hyadesia uncinifer Megnin, 1889 

Discussion: These mites are found in the tidal zone, on sea algae. 
Michael 1901 reports finding large numbers of Hyadesia algivorans 



340 Acarology 

(Michael) in a patch of green alga "growing where the fresh water of 
a small stream trickled over the face of the granite cliffs within reach 
of the spray of the sea, near Lands' End, Cornwall." Michael says 
these mites are not swimmers but "crawlers, frequenting algae and 
stones in shallow water, or even left dry between tides, or living in 
places where fresh water trickling over rock becomes mixed with salt 
spray, and the growth of green algae takes place; but they are evidently 
capable of living comfortably under water." Halbert 1920 found Hya- 
desia fusca (Lohmann) "in numbers at edges of rock crevices in the 
Pelvetia and Spiralis zones at Malahide, June 1916. In the same local- 
ity it was found fairly common in rock-pools containing much Entero- 
mopha, in the Orange Lichen zone, July and September. First recorded 
as a British species from Clare Island, where it is abundant amongst 
coralline seaweeds in rock-pools. Lohmann gives its distribution as the 
North Sea and the Baltic." Hyadesia uncinijer Megnin has been re- 
ported as being semiaquatic in Tierra del Fuego, South America. The 
four known species are: uncinijer Megnin, algivorans {Michael), fusca 
(Lohmann), and kerguelenensis Lohmann. 

References: 

Andre, M. 1931. Sur le genre Hyadesia Megnin 1889 (Sarcoptides hydro- 
philes). Bull. Paris, Mus. d'Hist. Nat., Ser. 2, 3 (6): 496-506. 

Halbert, J. N. 1915. Acarinida: II. Terrestrial and Marine Acarina. Clare 
Island Survey, 31 (39), Section II, pp. 45-136, Pis. 4-8. 

. 1920. The Acarina of the sea-shore. Proc. Roy. Irish Acad. 35, Sect. 

B, pp. 106-152. 

Michael, A. D. 1901. British Tyroglyphidae 1: 200. 

Carpoglyphidae Oudemans, 1923 

Figure 267 

Diagnosis: These mites have a skin which is smooth but not shiny. 
They may have a propodosomal shield (Carpoglyphus) or be armored 
and lack a specially circumscribed propodosomal shield (Ferminia) . 
A pair of vertical setae is present and the propodosoma and hystero- 
soma are not separated by a suture. All tarsi have stalked claws and 
caruncles. The female genital opening reaches anteriorly to the medi- 
anly united apodemes of coxae ii; the male genital opening lies be- 
tween coxae IV (Carpoglyphus) , or behind coxae iv (Ferminia). The 
male lacks adanal genital suckers and suckers on tarsi iv. 



Sarcoptiformes 



341 



Genera: 

1. Carpoglyphus Robin, 1869 

Type. Acariis Icictis Linnaeus, 1758 {— Carpoglyphus anonymus 
Haller, 1882 = C. passulorum Robin, 1869) 

2. Ferminia Oudemans, 1928 

Type. Glycyphagus fuscus Oudemans, 1902 



Discussion: Carpoglyphus lactis 
(Linnaeus) is a widely distributed 
species to be found on dried fruits, 
milk products, glucose, decaying 
potatoes, flour, and many other 
food products. It has been re- 
corded as breeding in large num- 
bers inside bottles of wine in Paris, 
maintaining itself on floating 
pieces of cork and drawing nour- 
ishment from the wine. Carpogly- 
phus alienus Banks, 1904 was 
found in urine of a patient with a 
kidney disease. Each time the 
patient passed urine these mites 
were found surrounded by puru- 
lent matter. The location of the 
type of the mite is not known and 
consequently the exact taxonomic 
status of the species cannot be de- 
termined but the figure indicates a 

true Carpoglyphus. The habitat suggests that of Dermatophagoides 
takeuchii Sasa. 




Figure 267 Carpoglyphus lactis (Lin- 
naeus). Venter of female. 



References: 

Andre, M. 1931. Presence d'Acariens dans les vins sucres. Bull. Soc. Zool. 

de France 56: 335-340. 
Banks, N. 1904. An alleged parasitic Tyroglyphid. Proc. Ent. Soc. Wash. 

8 (1): 40-42. 
Michael, A. D. 1903. British Tyroglyphidae, Vol. 2. 
Oudemans, A. C. 1926. Krit. hist. Overz. Acarol., L Tijdschr. v. Entom., 

LXIX, Suppl., pp. 218, 225. 



342 



Acarology 



Oulenziidae Oudemans, 1928 

Figure 268 




Figure 268 Oulenzia arboricola 
(Oudemans). Dorsum of female. Note 
eyes on lateral margins of propodo- 
soma. 



Diagnosis: The oulenziids have 
a propodosomal shield which is 
not strongly sclerotized as in some 
groups. Their skin is wrinkled. On 
the rear of the propodcsoma lies 
a transverse row of four setae, 
the inner pair being much shorter 
than the outer. In place of the 
cervical seta on each side of pro- 
podosoma is a lenshke eye. A 
pair of vertical setae are present. 
The female genital opening is sit- 
uated between coxae in and iv. 
All tarsi are slender, with stalked 
claws and caruncles and with 
minute spines. Males are not 
known. 



Genus: 

Oulenzia Radford, 1950 (= Lenzia Oudemans, 1928, nom. praeocc.) 
Type. Lenzia arboricola Oudemans, 1928 

Discussion: This mite, the only known species, was found on leaves 
of Hevea in Sumatra; specimens were also collected on jute in India. 
Like Czenspinskia it is probably a vegetable feeder. 



References: 

Oudemans, A. C. 1928. Acarologische aanteekeningen XCI. Lenziidae, 

n. fam. Ent. Bar. 7(161): 327, 328. 
Radford, C. D. 1950. Systematic check list of mite genera and type species. 

Union Internat. des Sci. Biol., Ser. C (Sec. Ent.) 1: 152. 



Sarcoptiformes 



343 



Ensliniellidae Vitzthum, 1924 

Figures 269-271 

Diagnosis: These mites have a 
propodosomal shield, and a shiny, 
smooth skin. On the rear of the 
propodosoma is a transverse row of 
four setae, the inner pair being 
either of the same length as the 
ouiQT (Ensliniella) OT much shorter 
{Riemia). There are no cervical 
setae but a pair of vertical setae is 
present. The tarsi have stalked 
claws and caruncles. The female 
genital opening is found between 
coxae III and iv while the male gen- 
ital opening is between coxae iv. 

Males do not have adanal copula- ^'S"*-^ ^^^ Emliniella parasitica Wxiz- 

^ , thum. Venter of female. (After Vitz- 

tory suckers or suckers on tarsi iv. thum 1925) 





Figure 270 EnslinieUa parasitica Vitz- 
thum. Venter of male. (After Vitz- 
thum 1925) 



Figure 271 EnslinieUa parasitica Vitz- 
thum. Venter of hypopial nymph. 
(After Vitzthum 1925) 



344 Acarology 

Genera: 

1. Ensliniella Vitzthum, 1925 

Type. Ensliniella parasitica Vitzthum, 1925 

2. Horstia Oudemans, 1905 

Type. Trichotarsus ornatus Oudemans, 1 899 

3. Mantidoglyphiis \'\izi\\\xm, 1940 

Type. Mantidoi^lyphus anastati Vitzthum, 1940 

4. /?/>/»/<:/ Oudemans, 1925 

Type. Riemia he s per id urn Oudemans, 1925 

5. Tortonia Oudemans, 1911 

Type. Trichotarsus intermedins Oudemans, 1901 

6. Vidia Oudemans, 1905 

Type. Vidia nndulata Oudemans, 1905 

Discussion: This is another little-known family. Ensliniella parasitica 
Vitzthum was collected on the resting larvae (Ruhelarve) of Odynerus 
(Eionotns) delphinalis Giraud, family Vespidae, Hymenoptera, in 
Germany; and Vidia undnlata Oudemans was taken from Prosopis 
conjormis Foerst., family Colletidae, Hymenoptera, in Italy. 

Reference: 

Vitzthum, H. 1925. Eine neue Milbengattung und-art als Parasit von 
Odynerus (Lionotus) delphinalis Giraud 1866. Deut. Ent. Ztschr., 
Heft IV: 289-305. 

Czenspinskiidae Oudemans, 1927 

F/>/r 272 

Diagnosis: A propodosomal shield is present, and the skin is shiny 
and finely striated. On the rear of the propodosoma is a transverse row 
of four setae, the inner pair much shorter than the outer. No cervical 
setae are present but a pair of vertical setae is present. All tarsi have 
stalked claws and caruncles are long, slender, and have minute spines. 
The female genital opening lies between coxae in and iv. Males are 
not known. 

Genus: 

Czenspinskia Oudemans, 1927 (= Donndorfia Oudemans, 1931) 
Type. Tyroglyphns heterocornus Michael, 1903 (adults) 



Sarcoptiformes 



345 



Discussion: Czenspinskia heterocomus (Michael) was beaten off 
oak trees in Hampshire, England, and was also taken in considerable 
numbers in the moss of a squirrel's summer nest. Michael 1903 reared 
a great many by feeding them 
pieces of fungus. Czenspinskia 
lordi Nesbitt 1946 was found on 
apple trees in Nova Scotia. They 
live in colonies near the midribs 
of the leaves, feeding on vegetable 
matter and apparently overwin- 
tering beneath lichens and old 
oyster-shell scales. No males have 
been found and the mite appar- 
ently reproduces parthenogeneti- 
cally. 



Figure 212 Czenspinskia lordi Nes- 
bitt. Dorsum of female. (After Nes- 
bitt 1946) 




References: 

Michael, A. D. 1903. British Tyroglyphidae 2: 106-109, PI. 33. 
Nesbitt, H. H. 1946. Three new mites from Nova Scotian apple trees. 
Canad. Ent. 78: 15-22. 



Winterschmidtiidae Oudemans, 1923 

Figures 273, 274 

Diagnosis: These mites have a propodosomal shield and a shiny skin. 
On the posterior part of the propodosoma is a transverse row of four 
setae of equal length. No cervical setae are present, but a pair of ver- 
tical setae is present. The legs are short and robust. All tarsi have 
stalked claws and caruncles. Ventro-distally the tarsi have one, and 
terminally two very strong spines (especially on tarsi i and ii). Male 
and female genital openings are between coxae iv. The male does not 
have adanal suckers or suckers on tarsi iv but does have a latero- 
ventral sucker on tarsus i. 



346 

Genus: 



Acarology 



Winterschmidtia Oudemans, 1923 

Type. Suidasia (?) hamadryas Vitzthum, 1923 





Figure 273 Winterschmidtia hamad- 
ryas (Vitzthum). Venter of female. 
(After Vitzthum 1923) 



Figure 274 Winterschmidtia hamad- 
ryas (Vitzthum). Dorsum of female. 
(After Vitzthum 1923) 



Discussion: Winterschmidtia hamadryas (Vitzthum) was found in 
the passageways of Eccoptogaster rugulosus Ratz. in Prunus insititia, 
Germany. W. crassisetosa Willmann was taken from larvae and pupae 
of a scolytid, Phloeotribus scarabaeoides, Italy. This suggests that re- 
lated species and genera should be found in bark beetle tunnels. To 
date very little has been done on the study of mites in such habitats. 

References: 

Vitzthum, H. 1923. Acarologische Beobachtungen 7. Reihe. Arch. f. 

Naturgesch., Abt. A, Hft. 2: 97-181. 
Willmann, C. 1939. Winterschmidtia crassisetosa spec. nov. (Winter- 

schmidtiidae, Acari). Boll. Lab. Zool. Generale e Agraria della 

Facolta Agraria in Portici, 31: 65-68. 



Sarcoptiformes 



347 



Lardoglyphidae Oudemans, 1927 

Figures 275, 276 i 

Diagnosis: These mites have propodosomal shield and a shiny skin. 
The body setae are smooth, a pair of vertical setae is present and the 
cervical setae are feathered. The tarsi have stalked claws and suckers. 
In the immature stages the claws are normal. Claws of the male on 
tarsi I and ii and those of the female on all tarsi are Y-shaped and 





Figure 273 Lardoglyphus zacheri 
Oudemans. Ventral view of male and 
of tarsus i. (After Oudemans unpub- 
lished) 



Figure 276 Lardoglyphus zcicheri 
Oudemans. Ventral view of female 
and tarsus i. (After Oudemans unpub- 
lished) 



forked. Tarsus iii of the male is forked but does not have a claw. The 
female genital opening lies between coxae in while the male genital 
opening is between coxae iv. Males have adanal copulatory suckers 
and two suckers on tarsi iv. 



Genus: 

Lardoglyphus Oudemans, 1927 

Type. Lardoglyphus zacheri Oudemans, 1927 

1 Our sincere thanks to D. Boschna and Mr. Hammen of the Rijksmuseum van 
Natuurlijke Historic, Leiden, Holland, for permission to use these unpublished figures 
of Oudemans. 



348 Acarology 

Discussion: Oudemans published very little on this group, apparently 
giving just enough information to include the mite in his key. 

Reference: 

Oudemans, A. C. 1927. Acarologische aanteekeningen LXXXVI. Ent. 
Ber. 7: 242-248. 



Olafseniidae Oudemans, 1927 

Figure 277 




Figure 277 Olafsenia trifoUiim 
(Oudemans). Dorsum of nymph. 
(After Oudemans 1901 ) 



Diagnosis: This family is known 
only from the homeomorphic nymph. 
It (according to Vitzthum) is proba- 
bly without a propodosomatic shield 
and has a smooth skin. On the poste- 
rior part of the propodosoma is a 
transverse row of two very long setae. 
There is also a pair of long setae on 
the shoulder and posterior of the 
hysterosoma. A pair of vertical setae 
is present as are marginal cervical 
setae which are weak and in the form 
of a bent spine. All tarsi have lance- 
like or spoonlike ''adhesive" setae. 
The tarsi have unsegmented claws 
and caruncles and the claws have a 
knoblike swelling on the venter. Epi- 
mera i form a Y. 



Genus: 

Olafsenia Oudemans, 1924 

Type. Tyroglyphus trifolium Oudemans, 1901 

Discussion: The single species, Olafsenia trifolium (Oudemans), a 
nymph, was collected from Heliocopris bucephalus from Java. 



Reference: 

Oudemans, A. C. 1901. Notes on Acari. Third series. Tijd. Dierkundige 
Ver., Ser. 2, 50-88. 



Sarcoptiformes 



349 



Chortoglyphidae Berlese, 1897 

Figures 278-280 



Diagnosis: The body of these mites 
is oval and there is no suture between 
the propodosoma and the hystero- 
soma. The skin is hard, smooth, and 
shiny. The dorsal setae are smooth 
and short (with the exception of the 
setae scapulares internae in Fusaca- 
rus) . A pair of vertical setae are pres- 
ent. The chelicerae are normal, scis- 
sor-shaped, or chelate. All tarsi have 
caruncles and tarsal claws are in- 
serted into the anterior or distal por- 
tions of the caruncles. The female 
genital opening lies between coxae 
III and IV while the male genital open- 
ing is between coxae i and ii. 




Figure 278 Chortogly pints arcuatiis 
(Troupeau). Dorsum of female. 
(After Zakhvatkin 1940) 





Figure 279 Chortoglyphus arcuatiis 
(Troupeau). Venter of male. (After 
Zakhvatkin 1940) 



Figure 280 Chortoglyphus arcuatus 
(Troupeau). Venter of female. (After 
Zakhvatkin 1940) 



350 
Genera: 



Acarology 



1. Chortoglyphus^QvXQSQ, \^M 

Type. Tyroglyphus arcuatus Troupeau, 1879 

(= Chortoglyphus midus Berlese, 1884) 

2. Fiisacanis Michael, 1903 

Type. Fusacarus laminipes Michael, 1903 

Discussion: Chortoglyphus arcuatus (Troupeau) has been recorded 
by Michael 1903 as being found on the floors and beams of an old 
barn and from an old stable in England, from stables and hay in Italy, 
as well as on rabbit excrement, on flour in France, in debris in freight- 
ers, and in a poultry house in Massachusetts. Fusacarus laminipes 
Michael has been taken from moles' nests (but not upon the mole) 
by Michael in England. 

References: 

Michael, A. D. 1903. British Tyroglyphidae 2: 1-12, Pis. XX, XXI. 

Zakhvatkin, A. A. 1940. Key to mites injuring stores of agricultural prod- 
ucts in U.S.S.R. (In Russian). Uchenye Zapiski Mosk. Godudarst 
Univ. No. 42Zool.: 7-68. 



Glycyphagidae Berlese, 1887 

Figures 281-284 




Figure 281 Glycyphagus genicidatus 
Vitzthum. Dorsum of female. (After 
Vitzthum 1931) 



Diagnosis: Rather broad in body, 
these mites usually do not have a 
suture between the propodosoma 
and the hysterosoma. A pair of 
vertical setae are present. The 




Figure 282 Glycyphagus domesticus 
(DeGeer). Hypopial stage. (After 
Hughes and Hughes 1938) 



Sarcoptiformes 351 

skin is smooth but not shiny or rough because of fine granulations or 
punctures. Dorsal setae are usually pilose, feathered, or fan-shaped. 
The chelicerae are normal and 

scissor-like. All tarsi are uniformly ^ -^ -^ '''^ ^ ^ 

pointed distally and have carun- 
cles. On the anterior or distal part 
of the caruncle is a tiny claw or 
sometimes a very large empodial 
claw. 





Figure 283 Fiisohericia incredibilis 
Vitzthum. Hypopial stage. (After 
Vitzthum 1931) 

Genera and subgenera: 



Figure 284 Fiisohericia incredibilis 
Vitzthum. Dorsum of female. (After 
Vitzthum 1931) 



6. 



7. 



S. 



Glycyphagus Hering, 1838 

a. Glycyphagus s. str. 

Type. Glycyphagus prunorum Hering, 1838 

b. Oudemansium Zakhvatkin, 1936 
Type. Acarus domesticus DeGeer, 1771 

Blomia Oudemans, 1928 

Type. Glycyphagus tjibodas Oudemans, 1910 

Cerop/?flgw5 Oudemans, 1 902 

Type. Cerophagus bomborum Oudemans, 1902 

Chaetodactylus Rondani, 1866 (= Trichotarsus Canestrini, 1888) 

Type. Trichodacty lus osmiae T>uiour, 1839 

Cometacarus Zakhvatkin, 1936 

Type. Cometacarus smirnovi Zakhvatkin, 1936 (deutonymph) 

Crastidoglyphus Oudemans, 1937 

Type. Acarus hyalinus Koch, 1841 

Ctenoglyphus Berlese, 1928 

Type. Glycyphagus canestrinii Armanelli, 1887 (= Acarus plumiger 

Koch, 1835) 
Dermacarus Haller, 1878 
Type. Homopus sciurinus Koch, 1842 



352 Acarology 

9. Fusohericia Wiizihum, \9?>\ 

Type. Fiisohericia incredibilis Vitzthum, 1931 

10. Gohiera Oudemans, 1938 

Type. Glycy phagiis fiiscus Oudemdins, 1903 

11. //t^Wc/fl Canestrini, 1888 

Type. Glycyphagus hericius Robin, 1868 

12. Labidophonis Kramer, 1877 

Type. Lahidophorus talpae Kramer, 1877 

13. Lepidoglyphiis Zakhvatkin, 1936 

ly^Q. Acarus destructor Schrank, 1781 (= A. cadaverum Schrank, 
1781) 

14. Melisia Lombardini, 1944 

Type. Melisia melisii Lombardini, 1944 

15. Sennertia Oudemans, 1905 

Type. Pediculus cerambycinus Scopoli, 1763 

16. Stroemia Oudemans, 1923 

Type. Dermacarus cantharobius Oudemans, 1905 

Discussion: The genus Glycyphagus is best known. G. domesticus 
(DeGeer) is found in dried fruits and organic matter such as skin and 
feathers, and is often found in enormous numbers in homes and stores. 
G. domesticus causes the "grocers' itch" when highly infested material 
is handled. Lepidoglyphus destructor (Schrank) (known in literature as 
Glycyphagus destructor or cadaverum) damages certain seeds in stor- 
age, lowering the germination of the seed. The seeds of Italian rye 
grass and Kentucky blue grass are susceptible to mite injury. In other 
seeds, damage is done to the already broken kernels, and as quoted 
from Prescott 1933 "the mites live essentially on broken grains, glumes, 
and other inert matter in the sample, and only, in certain cases, are 
they capable of attacking sound germinable grains to such an extent 
as to have any injurious effects on these grains." Joyeux and Baer 
1945 report Glycyphagus domesticus (DeGeer) as the intermediate 
host of Catenotaemia pusilla (Goeze), a cestode parasite of ro- 
dents. This is an interesting observation in view of the role the related 
oribatid mites play to the sheep tapeworm, Moniezia expansa (Ru- 
dolphi ) . 

Hughes and Hughes (1938) 1939, have published on the anatomy 
and post-embryonic development of Glycyphagus domesticus (De- 
Geer). There is an egg, a larval, and a protonymphal stage; at the end 
of the protonymphal stage the nymph may pass into the resting stage 
to give rise to an active deutonymph, or it may pass into an hypopial 
stage, remaining surrounded by the cast skin of the protonymph. This 



Sarcoptiformes 353 

hypopial stage may rest as long as six months before giving rise to the 
active deutonymph. Michael 1901 states that the hypopus of G. spi- 
nipes (Koch), however, is fully formed and capable of moving its 
legs but is not able to walk. In the Acaridae, for example, the hypopi 
are active and usually attach themselves on some insect or large mite 
and are carried about. In no case, however, does the hypopus feed. 
The deutonymph is very similar to the adult into which it changes 
after a short resting period. 

Rejerences: 

Andre, M. 1941. Invasions de Glycyphages (Acariens). Bull. Soc. Zool. 

de France 66:142-148. 
Hughes, T. E., and A. M. Hughes. 1939 (1938). The internal anatomy and 

post-embryonic development of Glycyphagus domesticus (DeGeer). 

Proc. Zool. Soc. London, Ser. B, 108(4) :714-733. 
Joyeux, Ch., and G. Baer. 1945. Morphologie, evolution et position sys- 

tematique de Catenotaenia pusilla (Goeze, 1782), Cestode parasite de 

Rongeurs. Rev. Suisse de Zool. 52(2) : 13-51. 
Prescott, R. T. M. 1933. Mites in seeds. J. Victoria Dept. Agr. (10) :519- 

523. 

Canestriniidae Berlese, 1884 

Figure 285 

Diagnosis: The body of these mites is hardly longer than it is wide 
and may be flattened, round or oval, pentagonal or diamond-shaped. 
The skin is either leathery or scaly. A pair of vertical setae is present, 
and the chelicerae are normal and scissor-shaped. The tarsal claws 
are frequently tiny and are completely wrapped up with the stalked 
caruncles. No olfactory, rodlike sensory setae are found on tarsi i and 
II. There are two pairs of genital suckers. Males may or may not have 
adanal copulatory suckers. 

Genera: 

1. Canestrinia Berlese, 1881 

Type. Canestrinia dorcicola Berlese, 1881 

2. Acrotacarus Banks, 1915 

Type. Acrotacarus mirabilis Banks, 1915 

3. Amansia Oudemans, 1937 

Type. Dermaleichus chrysomelinus Koch, 1841 

4. Canestriniella Berlese, 1910 

Type. Canestriniella amplexans Berlese, 1910 



354 



Acarology 



6. 



10. 



11. 



12. 



13. 



14. 



15. 



16. 



Caraboecius Cooreman, 1950 

Type. Caraboecius coriacei Cooreman, 1 950 

ColeoglyphiisBcrXQSQ, \9\0 

Type. Coleoglyphiis fuscipes Berlese, 1910 

Coleopterophagiis Berlese, 1882 

Type. Dennoglyphus megninii Berlese, 1881 

Dicanestrinia Berlese, 1911 

Type. Dermaleichiis cerambycis G. Canestrini, 1878 

Grandiella Lombardini, 1938 

Type. Grandiella tetracaudata Lombardini, 1938 

Megacanestrinia Tragardh, 1906 

Type. Megacanestrinia mucronata Tragardh, 1906 

Paramansia Cooreman, 1950 

Type. Paramansia menthastri Cooreman, 1950 

Percanestrinia Berlese, 1911 

Type. Alloptes blaptis Canestrini and Berlese, 1880 

Photia Oudemans, 1904 {— Eucanestrinia Berlese, 1911) 

Type. Canestrinia procrustidis Berlese, 1881 

Procericola Cooreman, 1950 

Type. Procericola ichthyo ides Cooreman, 1950 

Pseudamansia Cooreman, 1950 

Type. Dermaleichiis chry somelinus Koch, 1841 

Rosensteinia Oudemans, 1923 

Type. Rosensteinia sieversi Oudemans, 1 923 

Discussion: Canestrinia dorcicola 
Berlese was taken from Dorciis paral- 
lelepipediis (L.), family Lucanidae, 
Coleoptera, Italy; Coleopterophagus 
megninii (Berlese) has been collected 
from under elytra of various species 
of Cetonia, Italy; Photia procrustidis 
(Berlese) was collected from under 
the elytra of Procrustes coriacei (L.), 
family Passalidae, Coleoptera; and 
Grandiella tetracaudata Lombardini 
was found on Phanaeus species, fam- 
ily Scarabaeidae, Coleoptera, Brazil. 



Figure 28^ Grandiella escaudata Lombar- 
dini. Dorsum of female. (After Lombardini 
1938) 




Sarcoptiformes 



355 



References: 

Cooreman, J. 1950. Etude de quelques Canestriniidae (Acari) vivant sur 
des Chrysomelidae et sur des Carabidae (Insecta Coleoptera). Bull. 
Inst. Roy. Sci. Nat. de Belgique 26(33) : 1-54. 

Lombardini, G. 1938. Acari Novi II. Mem. Soc. Ent. Ital. 17:118-120. 

. (1943) 1944. Acari. Un Nuovo Genere della famiglia 'Tyro- 

glyphidae." Redia 30:1-24. 

. 1950. Canestriniidae deH'America del Sud (Acarina). Arthropoda 

1(2/4): 279-290. 



Hemisarcoptidae Oudemans, 1908 

Figure 286 



Diagnosis: Measuring about 0.23 to 
0.34 mm. in length, these mites have an 
egg-shaped body. Their skin is smooth, 
shiny, and they have a propodosomal 
shield. Vertical setae are present. The 
chelicerae are normal, scissor-shaped, 
but not denticulate. The legs are short 
and robust. All tarsi lack claws, but the 
tip of the tarsus has two strong clawlike 
spines, with the long stalk of the bell- 
shaped caruncle attached between 
them. There is*no sexual dimorphism. 
Male and female genital openings are 
far behind coxae iv. Two pairs of geni- 
tal suckers are present. Males lack ada- 
nal copulatory suckers. Tarsi in and iv 
each have a long whiphke seta. 




Figure 286 Hemisarcoptes mains 
(Shimer). Venter of female. 



Genus: 



Hemisarcoptes Lignieres, 1893 
Ty^Q. Acarus mains Shimer, 1868 
Lignieres, 1893) 



( = Hemisarcoptes coccisugiis 



Discussion: Hemisarcoptes malus (Shimer), the only species in the 
family, is widely distributed and is to be found associated with scale 
insects. It feeds upon the eggs or the scale itself and at times is nu- 



356 Acarology 

merous enough to be of material importance in reducing the popula- 
tion. It has been found preying on many species, among which are the 
following: 

Lepidosaphes ficiis (Sign.), on fig, CaUfornia 

L. iilmi L., in France, Germany, Pennsylvania, and eastern Canada 

L. becki (Newman), on citrus, California 

Parlatorio oleae, on olive, California 

Aspidiotus latanae, in insectaries, California 

Diaspis canieli Targ., on cypress, Bermuda 

Aonidiella perniciosa Comstock, in France 

Chionaspis salicis L., in Germany 

The eggs of Lepidosaphes appear to be the favorite food. Tothill 1918 
studied the mite and found it "perhaps even more useful than has been 
supposed." In certain areas of eastern Canada he found the oyster- 
shell scale controlled by the mite. He states: "It at least seems certain 
that when the scale is abundant this mite is the most important single 
factor operating toward control in eastern Canada. In places where 
the host is less abundant, the mite becomes proportionately less effi- 
cient." Hemisarcoptes mains (Shimer) was found attacking the latana 
scale, Aspidiotus latanae being reared in the insectary of the Citrus 
Experiment Station, Riverside, California, for parasite studies. Cor- 
respondence from B. Bartlett and P. DeBach stated that the work on 
rearing was being disrupted by this mite. 

References: * 

Andre, M. 1942. Sur I'Hemisarcoptes malus Shimer (= coccisugus 
Lignieres) (Acariens). Bull. Paris Mus. d'Hist. Nat., Ser. 2, 14(3): 
173-180. 

Ewing, H. E., and R. L. Webster. 1912. Mites associated with the oyster- 
shell scale (Lepidosaphes ulmi Linne) Psyche 19:121. 

Lord, F. T. 1947. The influence of spray programs on the fauna of apple 
orchards in Nova Scotia: II. Oyster-shell scale. Canad. Ent. 79(11, 
12): 196-209. 

Shimer, H. 1868. Notes on the apple bark-louse (Lepidosaphes conchi- 
fonnis, Gmelin sp.), with a description of a supposed new Acarus. 
Trans. Amer. Ent. Soc. 1:368. 

Tothill, J. D. 1918. The predaceous mite, Hemisarcoptes malus Shimer, 
and its relation to the natural control of the oyster-shell scale, Lepi- 
dosaphes ulmi L. Agr. Gaz. Canada 5(3) : 234-239. 



Sarcoptijorm es 357 

Ewingidae Pearse, 1929 

Figure 287 

Diagnosis: The body of the ewingids is 

egg-shaped and has a few setae. Vertical 

setae are present. On the rear of the pro- 

podosoma is a transverse row of two long 

setae. No suture separates the propodo- 

soma and the hysterosoma. There is one 

pair of long setae on the anterior portion 

of the hysterosoma; few other minute 

body setae are present. The two-segmented 

palpi appear to form a tube enclosing the 

deformed chelicerae, which are not chelate ^'g»""^ ^^^ Ewingia cenobitae 

i_ ^ 1 1 *u ui u 1 • Pearse. Venter of female. 

but have only the movable chela remam- ^^^^^^ Pearse 1929) 

ing. Tarsi i and ii have claws but lack 

caruncles; legs in and iv are enormously thickened and transformed 
into clasping organs without tarsal claws but with tarsi adapted as 
claws. The genital opening lies between coxae in and iv and has (?) 
two pairs of genital suckers. 




Genus: 



Ewingia Pearse, 1929 

Type. Ewingia cenobitae Pearse, 1929 



Discussion: Ewingia cenobitae Pearse is to be found in the gills of 
the land hermit crab, Cenobita diogenes (Latreille), at Loggerhead, 
Dry Tortugas, Florida. The mites cling near the outside of the gills 
by means of the clasping adaptations of legs in and iv and the body 
lies between the gill lamellae. Eggs containing fully developed larvae 
apparently ready to hatch have been seen within several of the females. 
The larvae possess six legs and are similar to the adults. Pearse also 
examined the ghost crab, Ocypoda albicans (Bosc), but found no 
mites. This may be due to the fact that these crabs often visit the 
ocean to bathe their gills, whereas the hosts of the mite visit the ocean 
only once each year to hatch their young. 

Reference: 

Pearse, A. S. 1929. Two new mites from the gills of land crabs. Carnegie 
Inst. Wash. Publ. 391:225-230. 



358 



A carology 



Anoetidae Oudemans, 1904 

Figures 288, 289 

Diagnosis: The shape of the body is often distorted by large protu- 
berances. A suture may or may not be found between the propo- 
dosoma and the hysterosoma. Also a propodosomal shield may or may 




Figure 288 Histiostoma hiimidiatus 
(Vitzthum). Dorsum of female. 
(After Vitzthum 1927) 



Figure 289 Histiostoma liumidiatiis 
(Vitzthum). Venter of female. (After 
Vitzthum 1927) 



not be present. Both vertical and cervical setae are found. The skin 
is usually smooth, but occasionally it may be strewn with tiny points. 
The chelicerae have only one sawlike chela (an exception is Ceder- 
hjelmia which has the two sawlike chelae), and the palpal tarsus has 
two conspicuous, laterally projecting structures. All tarsi have slightly 
curved, unstalked claws but lack caruncles. Adults usually have four 
large organs in the shape of a ring or shoe located in the region of the 
coxae. Only the deutonymph possesses two pairs of genital suckers. 

Genera: 

1. Atwetiis Dujardin, 1842 (= Nodipalpiis Karpelles, 1893) 

Type. Hypopiis alicola Dujardin, 1849 (= Anoetus discrepans Oude- 
mans, 1903) 

2. Anoetoglyphus WXzihum, 1927 

Type. Anoetoglyphus ateiichi Vitzthum, 1927 



Sarcoptiformes 359 

3. Cederhjelmia Oudemans, 1931 

Type. Cederhjelmia quadriuncinata Oudemans, 1931 

4. Chiropteranoetus Womersley, 1942 

Type. Chiropteranoetus chalinoiobus Womersley, 1942 

5. Creutzeria Oudemans, 1932 

Type. Creutzeria tobaica Oudemans, 1932 

6. Glyphanoetus Oudemans, 1929 

Type. Glyphanoetus fulmeki Oudemans, 1929 

7. Histiostoma Kramer, 1876 (= Zschachia Oudemans, 1929) 

Type. Hypopus feroniarum Dufour, 1839 (= Tyroglyphus rostroser- 
ratiis Megnin = Histiostoma pectineum Kramer, 1876) 

8. Mauduytia Oudemans, 1929 

Type. Anoetus tropicus Oudemans, 1911 

9. Myianoetus Oudemans, 1929 

Type. Acarus muscarum Linnaeus, 1758 

10. Prowichmannia Radford, 1950 (= Wichmannia Oudemans, 1929, 

nom. praeocc.) 
Type. Histiostoma spiniferum Michael, 1901 

11. 5W/efl Oudemans, 1929 

Type. Histiostoma pulchrum Kramer, 1886 

12. Zwickia Oudemans, 1924 

Type. Anoetus guentheri Oudemans, 1915 

Discussion: The Anoetidae are usually to be found in damp places 
such as in the sap of trees around wounds, in rotten damp fungi, in 
Drosophila cultures, in rotting potatoes, and in similar habitats. The 
deutonymphs. hypopial forms, or travelers are to be found on insects. 
One of our most common species is Histiostoma jeroniarwn (Dufour). 
Michael 1901 gives the following information under habitat. "Megnin 
found the species originally wading in great quantities in the thin film 
of liquid which covers decaying mushrooms. It is hardly an exaggera- 
tion to say that it may be found on all kinds of damp, decaying, soft 
vegetation which has substantial thickness; it is perhaps most abundant 
on fungi and roots, but it is very generally distributed; it is extremely 
abundant. The species has been recorded in France, Germany, Italy, 
and Switzerland; it is found in all parts of England. It is, I think, a 
follower, not an initiator of decay." The life cycle of Zwickia guen- 
theri Oudemans is well illustrated in Vitzthum 1931; the larval, pro- 
tonymphal, deutonymphal (hypopial or traveling stage), tritonymphal, 
and adult (male and female) stages are represented. Womersley 1941 
gives a key to the genera of the Anoetidae based upon the deuto- 
nymphs. 



360 



Acarology 



References: 

Cooreman, J. 1941. Etudes Biospeologiques. XXVIII (1). Note sur 

Myianoetiis dicidematiis Willmann, 1937 (Acariens, Sarcoptiformes) 

Pseudoparasite des Helomyzidae (Dipteres) de Transylvanie. Bull. 

Musee Royal d'Hist. Nat. Brussels 17(42) : 1-16. 
. 1947. Le stade adulte de Myianoetus muscarum (Linne). Bull, et 

Ann. Soc. Ent. de Belg. 73:141-149. 
Hughes, R. D. 1950. The genetics laboratory mite Histiostoina Uihora- 

tor'nim, n. sp. (Anoetidae). J. Wash. Acad. Sci. 40(6) : 177-182. 
Michael, A. D. 1901. British Tyroglyphidae 1. 
Vitzthum, H. 1931. Terrestrische Acarinen der Deutschen Limnologischen 

Sunda-Expedition. Suppl. Bd. IX 'Tropische Binnengewasser. Arch. 

f. Hydrobiol. Band II: 59-134. 
Womersley, H. 1941. Studies in Australian Acarina (2) Tyroglyphidae 

(s.l.). Rec. South Austral. Mus. 6(4) :451-488, 



Linobiidae Oudemans, 1908 

Figures 290, 291 




Figure 290 Linohia coccinellae (Sco- 
poli). Dorsum of female. (After Ber- 
lese 1887) 



Diagnosis: The body of these 
mites is broadly oval or pentago- 
nal and there are no vertical setae 
and no propodosomal shield. The 
skin is otherwise smooth. The 
chelicerae have only a sawlike, 
movable chela. All tarsi are claw- 
like but lack claws and have 
stalked caruncles. There are no 
rodlike sensory setae on tarsi i 
and II. Two pairs of genital suck- 
ers are present. The males lack 
copulatory suckers. 




Figure 291 Linohia coccinellae (Sco- 
poli). Chelicera. (After Berlese 1887) 



Genus: 

Linohia Berlese, 1884 (= Linocoptes Berlese, 1887) 
Type. Acarus coccinellae Scopoli, 1763 



Sarcoptiformes 



361 



Discussion: The only known species, Linobia coccinellae (Scopoli), 
has been taken from under the elytra of Melasoma populi in Italy. 

Reference: 

Berlese, A. 1887. Acari, Myriopoda et Scorpiones, Crypt. Fasc. XXXIX, 

No. 7. 

Nanacaridae Oudemans, 1923 

Figures 292, 293 

Diagnosis: These mites have a shiny skin and possibly no propo- 
dosomal shield. On the posterior part of the propodosoma is a cross 
row of four setae, the inner pair being much shorter than the outer. 




tz^> 




Figure 292 Nanacarus minutiis 
(Oudemans). Dorsum of female; 
tarsus II of female. (After Oudemans 
1928) 



Figure 293 Nanacarus minutus 
(Oudemans). Venter of female. (After 
Oudemans 1928) 



There are no cervical setae, but a pair of vertical setae is present. Male 
and female genital openings are behind coxae iv. The males have ad- 
anal copulatory suckers but do not have suckers on tarsi iv. All tarsi 
have only a caruncle and no claws, (in the immature stage there is 
a weakly developed claw). The tarsal tip is pointed, clawlike, and 
curved; legs without long, whiplike setae. 

Genera: 

1. Nanacarus Oudemans, 1902 (= Froweinia Oudemans, 1923) 
Type. Hypopus minutus Oudemans, 1902 

2. Giardius Perraud, 1896 

Type. Giardius vitis Perraud, 1896 



^62 Acarology 

Discussion: Nanacarus minutus (Oudemans) has been taken on 
Megapodius buruensis, Burn Islands; on Koptorthosoma te<miscapa, 
Java; and on Vesper ugo serotinus, Vesper tilio pipistrellus, and Sorex 
vulgaris, Germany. This species and Giarciius vitis Perraud are the 
only two known in this family. 

Sarcoptidae Trouessart, 1892 

(= Acaridae Oudemans, 1904 of European workers) 
Figures 294, 295 

Diagnosis: The sarcoptids are skin parasites of warm-blooded ani- 
mals. Their body shape is globose and there is no distinct suture be- 





Figure 294 Notoedres cati (Hering). 
Tarsus i. (After Grandjean 1938) 



Figure 295 Sarcoptes scabiei var. eqiii 
(Gerlach). Dorsum of female. (After 
Hirst 1922) 



tween the propodosoma and hysterosoma. A propodosomal shield may 
or may not be present. There is a pair of vertical setae on the propo- 
dosoma. In other areas the skin has fine striae which are often inter- 
rupted by scaly areas or by areas strewn with small points or spines. 
The legs are very short and may or may not have caruncles- or claws. 
No genital suckers are present. 

Genera: 

1. Sarcoptes Latreille, 1802 (= Acariis of Vitzthum) 
Type. Acarus scabiei DeGeer, 1778 



Sarcoptiformes 363 

2. Knemidokoptes Fiirstenburg, 1870 (= our Cnemidocoptes) 
Type. Sarcoptes mutans Robin and Lanquetin, 1859 

3. NotoedresR^\\\\eX.\?>93> 

TypQ. Sarcoptes cati Hering, 1838 (= Sarcoptes minor var. cati 
Railliet, 1893) 

4. Nycteridocoptes Oudemans, 1897 

Type. Nycteridocoptes poppei Oudemans, 1897 

5. Prosopodectes C^nQ^ix'mi, 1897 

Type. Sarcoptes chiropteralis Trouessart, 1896 

6. Teincoptes Rodheim, 1923 

Type. Teinocoptes epomorphi Rodheim, 1923 

7. Trixacarus Sellnick, 1944 

Type. Trixacarus diversus Sellnick, 1944 

Discussion: The Sarcoptes scabiei of man and other animals such as 
dogs, cattle, pigs, sheep, goats, camels, rabbits, and horses are mor- 
phologically alike but probably consist of biological races. The spe- 
cies from horse, for example, can attack man but will not usually 
produce a permanent infestation. 

Mellanby 1943 has presented an excellent review of the scabies 
mite in England from which most of the following account is taken. ^ 
The life cycle is very simple, consisting of egg, larva, nymph, male 
adult, immature, and mature female. The transformation of the im- 
mature female to the ovigerous female probably takes place after fer- 
tilization. A new victim is successfully infected in all probability by 
newly fertilized females which can move rapidly on warm skin. The 
mite takes about one hour tO bury itself into the homy layer of skin 
and goes no deeper. The burrowing is accomplished by the suckers 
adhering to the skin and the legs and mouth parts cutting into the 
host. The mature female usually stays in the burrow her entire life. 
She may remain in the burrow for three weeks and then leave, appar- 
ently of her own accord. The mite begins egg-laying within a few 
hours after starting her burrow, laying eggs at two- to three-day in- 
tervals for about two months, stringing the eggs out behind her as she 
lengthens her burrow. In the thick, horny layer the mite does not raise 
a lump but in the thinner skin the mite raises a tiny lump. Eggs may 
hatch in three to eight days at 35° C, although usually it takes about 
five days. The larvae leave the burrows and move about on the skin 
looking for shelter and probably food. Larvae and nymphs are to be 

1 1 am indebted to G. W. Eddy for reviewing this section and adding his own obser- 
vations made on "self-infection" with gravid female mites. 



364 Acarology 

found in the skin follicles. The adult male or immature female emerges 
within four to six days after 'the egg hatches. The male, which is rare, 
is found in a short burrow where it remains for a brief period, since 
it spends a considerable time on the skin surface searching for unfer- 
tilized females. Although the unfertilized female makes a small bur- 
row it stays in it for only a day or so. Mating probably takes place on 
the skin. The cycle from egg to ovigerous female takes from ten to 
fourteen days. Less than 10 per cent of the eggs give rise to adults. 
Movement or burrowing usually follows egg deposition. 

The mites cause severe itching which keeps the patient awake at 
night. Itching is associated directly with burrowing; each time the mites 
irritated the skin or caused itching they were found to be moving on. 
There is a characteristic rash, due both to the mite and to scratching. 
Erythematous patches and follicular papules appear in areas under the 
arms, around the waist, on the wrists, between the legs, on the thighs, 
and on the ankles. Most of the skin symptoms are due to secondary 
infections which follow scabies. It is believed that the first case of 
scabies causes no itching. After a month or so, when the rash appears 
in the area of the burrows, the itching begins since the patient has now 
become sensitized to the mite. Once having had scabies and acquiring 
another infection, the area around the burrow becomes inflamed within 
a few hours. A sensitized person begins to scratch immediately and 
often is able to dislodge the Sarcoptes and automatically stops the in- 
fection, whereas in the nonsensitized person the infection builds up 
over a period of about a month before the patient is aware of harbor- 
ing the mites. 

Scabies is common in the history of man and appears to come in 
waves. Sensitization forms a so-called immunity and the mites can be 
located easily and dislodged. The next group of people have not been 
infected and are not sensitized and the mite population builds up as 
in diseases. The real causes of the rise and fall may not yet be known. 
The highest incidence is in winter when people sleep together to keep 
warm and there is less washing. Scabies is not acquired through ordi- 
nary social contacts but through sleeping in the same bed with an 
infected person. 

Secondary infections due to scratching are often more serious than 
the actual scabies. Reaction to different sulfur compounds used to con- 
trol the mite may also set up a serious skin condition. 

Sarcoptes mange of the dog is caused by Sarcoptes scabiei var. canis. 
It is to be found on any part of the animal but usually first on the head. 



Sarcoptijormes 365 

It spreads rapidly. Hirst 1922 lists the symptoms as follows: "There 
are reddish spots rather like flea bites, and the scratching of the ani- 
mal causes reddish places and papules to appear. The infected part 
often becomes dry and covered with yellowish crusts. The hair falls 
out and the skin becomes thickened, wrinkled and creased. Pruritus is 
intense. The presence of the parasite is the chief distinctive feature." 
Human beings may become infected with the dog Sarcoptes. The mite 
is apparently cosmopolitan. Sarcoptic mange of pigs, caused by S. 
scabiei var. sids, is common in the United States as well as in other 
countries. The general symptoms are as in the scabies of the dog. This 
species can also be transferred to man. Sarcoptes scabiei var. ovis 
Megnin is parasitic on sheep, where it is to be found around the head 
although in more serious cases the limbs and rarely the body become 
affected. It is not to be found on the wooly parts of the body. This 
mite can be transmitted to goats. Sarcoptes scabiei var. caprae FUr- 
stenburg can frequently cause the death of goats. This mite has been 
transmitted to man, horses, sheep, cattle, and pigs. 

The genus Notoedres contains mites causing mange in various ani- 
mals. N. cati Hering is the cause of mange in cats, which usually starts 
around the head, forming crusts until the skin becomes hard, thick- 
ened, and creased like leather. It is usually restricted to the head and 
neck. The mite has caused mange in dogs. Essi^ 1929 has recorded 
it as a pest of the wild gray squirrels in California, sometimes even 
causing their death. Notoedres cati var. cimicidi Gerlach attacks the 
rabbit, especially around the head, although in serious cases it may 
extend to the legs and genital regions. Notoedres muris Megnin is 
parasitic on the common brown rat and may be fatal. Both tame and 
wild rats are attacked by this mite. 

Knemidokoptes /nutans Robin and Lanquetin causes the scaly-leg 
of fowl and small domestic birds. Hirst describes it thus: "The large 
scales of the tarsus of the feet are first affected, becoming raised at the 
edges by whitish floury powder, which is sometimes mixed with exuded 
serum. In advance cases the disease assumes a characteristic form, the 
feet becoming greatly distorted and covered with thick nodular spongy 
crusts. The comb and neck may also be attacked." Scaly-leg is highly 
contagious. The depluming itch of poultry is caused by Knemidokop- 
tes laevis var. gallinae (Railliet). The mites, which are embedded in 
the tissue or scales at the base of the quills, cause a falling out of 
feathers over more or less extended areas of the body. It is to be 
found both in North America and Europe. K. laevis Railliet was de- 



366 Ac urology 

scribed from pigeons. Other birds such as pheasants and geese suffer 
from a depluming itch in France. 

References: 

Baker, D. W. .1946. Barn Itch. N.Y. State Vet. Col, Vet. Expt. Sta., 

Parasit. Lab., 36 pp. 
Friedman, R. 1942. Biology of Acarus scabiei, 183 pp. Froben Press, N.Y. 
Grandjean, F. 1938. Observations sur les acaridiae (1 serie) Bull. Soc. 

Zool. France 63(4-5) : 21 4-224. 
Hirst, S. 1922. Mites injurious to domestic animals. Brit. Mus. (Nat. 

Hist.) Econ. Ser., No. 13. 
Imes, Marion. 1918. Cattle Scab. U.S. Dept. Agr. Farmers' Bull. 1017 

(revised 1935). 
. 1924. Sheep Scab. U.S. Dept. Agr. Farmers' Bull. 713 (revised 

1927, 1935). 
Mellanby, K. 1943. Scabies. Oxford Univ. Press. London. 81 pp. illus. 
van Eyndhoven, G. L. 1947 (1945). Beschrijving van een nieuwen vleer- 

muisparasiet Notoedres vanschaiki v. Eyndh. 1946 (Acar.). Tijd- 

schrift V. Ent. 88:132-154. 



Cytoditidae Gudemans, 1908 

Figure 296 




Figure 296 Cytodites niidiis (Vizioli). 
Venter of female. (After Hirst 1922) 



Genus: 



Diagnosis: The cytoditids are me- 
dium-sized mites measuring from 
0.45 to 0.60 mm. long and shaped 
Hke an egg. Their skin is smooth 
dorsally but has fine striae in all 
other regions. There are no vertical 
setae and only a few tiny, dorsal 
setae. The gnathosoma is terminal 
and the chelicerae and pedipalps 
are fused into a sucking tube. All 
tarsi have caruncles on long stalks 
without claws. No genital suckers 
are present. Males do not have 
adanal copulatory suckers. 



Cytodites Megnin, 1877 (= Cytoleichus Megnin, 1880) 

Type. Sarcoptes nudus Vizioli, 1870 {— Cytodites glaber Megnin, 

1877) 



Sarcoptiformes 



367 



Discussion: Cytodites nudus (Vizioli) is to be found in chickens in 
the air sacks and respiratory system, in the body cavity in general, 
among and on the surface of the hepatic lobes and similar places. The 
presence of small numbers does not appear to damage the host, but 
large numbers may be of some importance. They have been accused 
of causing enteritis and peritonitis in fowl and can produce suffoca- 
tion by being present in large numbers in the air passages and sacks. 
Myers 1923 states that C. nudus brings forth living young with three 
pairs of legs. 

Reference: 

Myers, J. G. 1923. The internal mite of the domestic fowl. New Zealand 
J. Sci. and Tech. 6(1):59-61. 



Laminosioptidae Vitzthum, 1931 

Figure 297 

Diagnosis: Very small mites meas- 
uring from 0.20 to 0.26 mm. in 
length, the laminosioptids have an 
elongated, slightly flattened figure. 
Dorsally smooth, their skin has fine 
striae in other regions. No vertical 
setae appear on the propodosoma. 
The body has a few long setae. The 
gnathosoma is normal and not visi- 
ble from above. The legs are short, 
especially i and ii. Tarsi i and ii 
lack both claws and caruncles; tarsi 
III and IV have minute caruncles on 
long stalks or pedicles. There are 
no genital suckers, and the males 
do not have adanal copulatory f(^"*^,. 
suckers. 




297 Lam 

) . Venter 
Hirst 1922) 



ino 
of 



sioptes 
female 



cysticola 
. ' (After 



Genus: 



Laminosioptes Megnin, 1880 (= Symplectoptes Railliet, 1885) 
Type. Sarcoptes cysticola Vizioli, 1870 

Discussion: Laminosioptes cysticola (Vizioli) is an internal parasite 
of the fowl. In Europe it is to be found by the millions in the cellular 



368 



Acarology 



tissue of turkeys. It destroys the fibers. The mite may be detected by 
the occurrence of calcareous cysts in the subcutaneous tissues, but the 
mites are to be found aUve in the tissues and not in the cysts which 
form around the dead mites. Deaths of birds have been reported due 
to heavy infestations. This species has also been reported from do- 
mestic fowl in this country. 

References: 

Hirst, S. 1922. Mites injurious to domestic animals. Brit. Mus. (Nat. Hist.) 

Eco. Ser., No. 13. 
Taylor, T. 1884. Microscopic observations. Internal parasites in domestic 

fowls. U.S. Dept. Agr., Dept. Rpt. 34:1-5. 

' Heteropsoridae Oudemans, 1908 

Figure 298 

Diagnosis: These mites are very 
small (about 0.22 mm. in length). 
The body is very plump and al- 
most circular in shape. No vertical 
setae are present. The apodemes 
of all coxae end free. All legs are 
very thick, of equal length, and are 
arranged radially. All tarsi have 
monstrous, broadly leaf-shaped 
caruncles; tarsi in and iv have ven- 
tral, clawlike spines pointing pos- 
teriorly. 




Figure 298 Heteropsorus pteroptopus 
Trouessart and Neumann. Dorsum of 
female. (After Vitzthum 1929) 



Genus: 

Heteropsorus Trouessart and Neumann, 1887 

Type. Heteropsorus pteroptopus Trouessart and Neumann, 1887 

Discussion: The single species is to be found on the skins of birds 
and has been collected on Acrocephalus anmdinaceus, Erithacus cy- 
anecula, Emberiza cirlus and E. schoeniclus in Italy and France. It 
apparently has not been found since its original discovery. 



Sarcoptiformes 



369 



Reference: 

Berlese, A. 1897. Acari Myriopoda et Scorpiones. Ordo Crytpostigmata 
(Sarcoptidae). Fasc. LXXVIII, No. 4. 



Myialgesidae Trouessart, 1907 

Figures 299, 300 




Diagnosis: These mites arp par- 
asitic on the Hippoboscidae, 
Diptera, and occasionally on 
Mallophaga. The body of the fe- 
male is broadly oval (broadly 
pear-shaped when pregnant). 
Males are not known. No suture 
separates the propodosoma from 
the hysterosoma. There are no 
vertical setae, but there is pro- 
podosomal shield. The skin other- 





Figure 299 Myialges caulotoon Spie- 
ser. Dorsum of female. (After Ferris 
1928) 



Figure WO Left, Myialges anchora 
Sergent and Trouessart. Tarsus i; 
right, Myialges caulotoon Spieser. Tar- 
sus I. (After Ferris 1928) 



wise is soft with fine striae. The median side of the palpi has groove- 
excavations with the ends of the deformed chelicerae almost surrounded 
by a tube. Tarsi ii, in, and iv lack claws but have a stalked caruncle; 
tarsi I have no claw or lobe and are shaped like an anchor. The legs are 
located on the anterior portion of the body. The genital opening of 
the female lies between coxae iv. No genital suckers are present. 

Generu: 

1. Myialges Sergent and Trouessart, 1907 

Type. Myialges anchora Sergent and Trouessart, 1907 

2. Myialgopsis Cooreman, 1944 

Type. Myialgopsis trinotoni Cooreman, 1944 

Discussion: There are three species, Myialges anchora Sergent and 
Trouessart, M. caulotoon Spieser, and Myialgopsis trinotoni Coore- 



370 



Acarology 



man. Ferris 1928 has found M. anchora "attached by their beaks to 
the body of the fly host," usually to the abdomen although one speci- 
men was found on the thorax; Sergent and Trouessart found them on 
both thorax and abdomen. The mites are true parasites of flies, and 
scars are formed at the point of attachment by the deposition of addi- 
tional chitin, an indication of long periods of attachment. Males arc 
not known and it has been suggested by some that they may be found 
on the.bird hosts of flies. 

References: 

Cooreman, J. 1944. Un nouveau cas d'hyperparasitism parmi les Acaridiae: 

Mykilgopsis trinotoni n. gen. n. sp. parasite d'un Mallophage. Bull. 

Mus. Roy. d'Hist. Nat. de Belgique 20(26) : 1-12. 
Ferris, G. F. 1928. The genus Myialges (Acarina: Sarcoptidae). Ent. 

News 39(5): 137-140. 
Oudemans, A. C. 1935. Description du Myialges anchora Sergent et 

Trouessart 1907 (Acarien). Ann. de Parasitol. Humaine et Compar. 

13(1):5-11. 



Psoroptidae Canestrini, 1892 

Figures 301, 302 




Diagnosis: With few exceptions 
the psoroptids are parasites of 
mammals. No vertical setae are 
present but there are dorsal 
shields. Bell-shaped caruncles are 
found on long, segmented stalks 
(Psoroptes), or short, unseg- 
mented stalks appear on all tarsi 
in the male (except on tarsi iv of 
Psoroptes) and, on tarsi i, ii, and 
IV in the female (except in Oto- 




Figure 301 Psoroptes eqiii var. ovis 
(Hering). Dorsum of male. (After 
Hirst 1922) 



Figure 302 Otodectes cynotis (He- 
ring). Tip of leg I. (After Grandiean 
1937) 



Sarcoptiformes 371 

dectes and Caparinae where they are on tarsi i and ii) . In the male legs 
IV are considerably shorter than in. Tarsi in of the females end in long, 
whiphke setae. The males have adanal copulatory suckers. The posterior 
margin of the abdomen of the male is bibolate or slightly emarginate. 

Genera: 

1. Psoroptes Gervais, 1841 (= Dermatodectes Gerlach, 1857 = Der- 

matokoptes FLirstenburg, 1861) 
Type. Sarcoptes equi Hering, 1838 

2. Caparinia Canestrini, 1894 

Type. Chorioptes setiferus Megnin, 1880 

3. Chorioptes Gervais, 1859 (= Symbiotes Gerlach, 1857 nom praeocc. 

= Dennatophagus FurstQnbuTg, 1861) 
Type. Sarcoptes caprae Delafond, 1854 

4. Otodectes Canestrini, 1894 

Type. Sarcoptes cynotis Hering, 1838 

Discussion: The genus Psoroptes can be considered as consisting of 
one species with the varieties existing upon the various hosts. These 
varieties are only slightly differentiated morphologically (Hirst 1922) 
and it is difficult or impossible to transfer the mites from one host to 
another of a different species. 

Psoroptes equi var. ovis causes the disease known as sheep-scab 
which damages the wool and at times causes the loss of the animals. 
The psoroptic mange differs from the sarcoptic mange in being found 
on the body wherever there is wool. The mites pierce the skin with 
their chehcerae, causing the characteristic irritation, scabs, and exu- 
dation of serum. The wool may become matted and even detached in 
some cases. The mites live under the scabs formed by the exudation 
of the serum at the site of the punctures and their activity continually 
adds to the thickness of the scab. Van Es 1904 states that "weak ani- 
mals or such as are not well cared for show the physical effects of the 
disease in the form of loss of flesh, anaemia, and an increased weak- 
ness which may be the forerunner of a fatal termination." They are 
readily transmittable through direct contact or through infected ma- 
terials. It is world-wide in distribution. 

Psoroptes equi var. caprae is to be found on goats but is confined 
to the ears. Usually the mite is not a serious pest but at times can 
cause deafness, loss of appetite, and, in extreme cases, death of the 
animal. 

Psoroptes equi var. cuniculi is to be found in the ear of rabbits and 



372 Acarology 

apparently attacks only the concha. Marine 1924 gives the following 
description of the symptoms: "The earliest manifestations of infection 
are indicated by hyperemia and the formation of reddish brown crusts 
near the bottom of the concha. The hyperemia and crust formation 
extend and after months may involve nearly all the inner surface of 
the ear. The most serious complication of the disease is pyogenic in- 
fection of the middle ear which may extend to the internal ear and 
meninges. The parasite spreads more rapidly during the warm months. 
The disease is widespread, and few, if any, laboratories escape its 
occasional introduction." 

Psoroptic mange is to be encountered on horses and cows. That of 
the horse is common in France and is also present in England. It is 
probably widespread. 

Psoroptes eqiii var. bovis causes the common cattle scab. As is the 
case with the other members of the genus the entire life cycle of the 
mite is passed upon the host. Imes 1918 reports: "The first lesions on 
cattle appear on the withers, on top of the neck or just in front of the 
withers, or around the root of the tail. From these points it spreads 
over the back and sides and unless checked it may involve practically 
the entire body. When a scab mite finds lodgment on the body it 
pricks the skin to obtain food and in so doing probably introduces a 
poisonous secretion into the wound. A slight inflammation is caused, 
but this early stage of the disease is rarely, if ever, detected by casual 
observation. As the mites multiply, large numbers of small wounds 
are made in the skin and are followed by intense itching, formation 
of papules, inflammation, and exudation of serum. The serum which 
oozes to the surface becomes mixed with particles of dirt and more 
or less infected with microorganisms. This mass soon hardens into 
yellowish or gray-colored scabs which frequently are stained with 
blood. In the early stages of the disease the scab may be about the 
size of a pea, but as the mites seek the healthy skin around the edges 
of the wound the scab or lesion gradually increases in size." 

The genus Chorioptes consists of several species which may actu- 
ally be nothing but physiological varieties as in Psoroptes. They are 
to be found on horses, cattle, sheep, goats and a few other animals. 
Chorioptes bovis (Gerlach) is usually restricted to the feet or to the 
base of the tail and anal fossa in cattle. In some cases it spreads on 
to the neck and back, or to the belly and perineum. This mange is 
usually of a mild type, remaining localized and spreading slowly. Other 
species are C. equi (Hering) on horse, C. caprae (Delafond) on goat. 



Sarcoptijormes 373 

C. ovis (Railliet) on sheep, and C. cuniculi (Zurn) on rabbit. 

Mites belonging to the genus Otodectes Uve in the ears of dogs, 
cats, ferrets, and fox. As with the above species they are structurally 
similar but are considered as varieties of Otodectes cynotis Hering. 
The mites cause a canker in the ears of cats in England and the pres- 
ence of the mites in dogs' ears causes the animal to shake its head 
constantly. 

References: 

Good, E. S. 1909. Sheep scab. Kentucky Agr. Expt. Sta. Bull. 1437, 219- 

246. 
Grandjean, F. 1937. Otodectes cynotis (Hering) et les pretendues tra- 

chees des acaridiae. Bull. Soc. Zool. France (4) : 280-290. 
Hirst, S. 1922. Mites injurious to domestic animals. Brit. Mus. (Nat. 

Hist.) Econ. Ser., No. 13. 
Imes, M. 1918. Cattle scab and methods of control and eradication. 

U.S. Dept. Agr. Farmers' Bull. 1017, pp. 1-29 (revised 1935). 
. 1924. Sheep scab. U.S. Dept. Agr. Farmers' Bull. 7-13 (revised 

1935). 
Marine, D. 1924. The cure and prevention of ear canker in rabbits. Sci- 
ence 60(1546) : 158. 
Van Es, L. 1904. Scabies in sheep and cattle and mange in horses. N. Dak. 

Agr. Col. Expt. Sta. Bull. 61:399-435. 

Epidermoptidae Trouessart, 1892 

(= Mealiidae Oudemans, 1923) 
Figures 303, 304 

Diagnosis: Very small mites measuring from 0.17 mm. to 0.39 mm. 
in length, the epidermoptids are rather flat, usually very short, and ap- 
proximately circular. A shield is present but is found only on the propo- 
dosoma in the females. There are no vertical setae on the propodosoma. 
The skin is soft and striated. The posterior of the male is often notched 
or bilobate while that of the female is rounded. The male possesses 
copulatory suckers. All tarsi end in caruncles. 

Genera: 

1. Epidermoptes Rivolta, 1876 

Type. Epidermoptes bilobatiis Rivolta, 1876 

2. Dermation Trouessart and Neumann, 1887 

Type. Epidermoptes bihamatiis Trouessart and Neumann, 1887 



374 



Acarology 



Dermatophagoides Bogdanow, 1864 (= Pachylichus G. Canestrini, 

1894 = Mealia Berlese, 1897) 
Type. Dermatophagoides scheremetewskyi Bogdanow, 1864 
Microlichus Trouessart and Neumann, 1887 
Type. Symbiotes avus Trouessart and Neumann, 1887 
Rivoltasia G. Canestrini, 1894 
Type. Epidennoptes hijurcatiis Rivolta, 1 876 
Turbinoptes Boyd, 1949 
Type. Turbinoptes strandtinanni Boyd, 1949 





Figure 303 Dermatophagoides scliere- 
metewskyi Bogdanow. Dorsum of fe- 
male. 



Figure 304 Dermatophagoides schere- 
metewskyi Bogdanow. Venter of fe- 
male. 



Discussion: These mites are usually to be found on the skin of birds. 
Epidennoptes bilobatus Rivolta lives on the skin of chicken and has 
been found in great numbers associated with pityriasis (scaly skin dis- 
ease) in some cases and has been accused of being the cause of the 
disease. Dermatophagoides scheremetewskyi Bogdanow 1864 was de- 
scribed from mites causing dermatitis in man. Traver 1951 reports 
on D. scheremetewskyi infesting the human scalp for a period of six- 
teen years. The first symptoms were small itching red papules accom- 
panied by the sensation of something crawling and scratching. The 
epidermis over the infested areas thickened and these regions became 



Sarcoptiform es 3 75 

swollen and painful. The mites did not remain upon the scalp, but on 
irritation caused by chemicals applied for control moved down from 
the head, invading the eyes, ears, and nostrils. The eyes became badly 
swollen and movement of the eyeballs was impossible. Invasion of the 
nostrils was accompanied by irritation of the throat, trachea, and 
bronchi. The mites were apparently confined to the pina region of the 
ears, forming itching papules. Small incrustations frequently covered 
infested areas. Possible sources of the infestation were pet cats and 
dogs suffering from "mange." Fisher et al. 1951 report on this same 
mite infesting the foot of a patient in conjunction with a fungus and 
causing a dermatitis. From the few case histories he suggests the pos- 
sibility that a dermatitis must first be present before the mite can 
establish itself. Sasa 1950 reviews the genus Dermatophagoides in 
Japan and reports finding D. takeuchii Sasa in urine, and D. saitoi Sasa 
in sputum from a patient with Loeffler's syndrome, and Dermatopha- 
goides sp. from sputum of a patient with chronic bronchial asthma. 

References: 

Boyd, E. 1949. A new genus and species of mite from the nasal cavity 
of the ring-billed gull (Acarina, Epidermoptidae). J. Parasitol. 35 
(3): 295-300. 

Cooreman, J. 1950. Sur un acarien nouveau, prejudiciable aux matieres 
alimentaires entreposees: Mealia maynei n. sp. Bull, et Ann. Soc. 
Ent. Belg. 86:164-168. 

Fisher, A. A., A. G. Franks, M. Wolf, and M. Leider. 1951. Concurrent 
infestation with a rare mite and infection with a common derma- 
tophyte. Archiv. of Dermatology and Syphilology 63(3) : 336-342. 

Sasa, M. 1950. Mites of the genus Dermatophagoides Bogdanoff, 1864 
found from three cases of human acariasis. Japanese J. Expt. Medi- 
cine 20:519-525. 

Traver, J. R. 1951. Unusual scalp dermatitis in humans caused by the 
mite Dermatophagoides. Proc. Ent. Soc. Wash. 53(1): 1-25. 

Psoralgidae Oudemans, 1908 

Diagnosis: These mites are rather flat and short bodied. The male 
has a deep posterior-median abdominal incision (bilobate). The skin 
is soft, wrinkled. A median dorsal shield is always present, but there 
are no other shields (?) nor are there any vertical setae. The che- 
licerae are chelate and the maxillae have two-segmented palpi. The 
legs are almost equal in size except in the male where legs in and iv 



376 Acarology 

are thicker (legs iii are even much longer). Both sexes have a bell- 
shaped caruncle on a short, unsegmented stalk. The male has adanal 
copulatory suckers. 

Genus: 

Psoralges Trouessart, 1896 

Type. Psoralges libertiis Trouessart, 1 896 

Discussion: These mites were found in the fur of Tamandua sp., a 
mammal. The larvae and nymphs live in colonies in subcutaneous 
bladders, causing a kind of itch; the adults live free among the hairs 
of the host. No figure is known. 



Listrophoridae Canestrini, 1892 

Figure 305 




Figure 30y Chirodiscoides caviae 
Hirst. Venter of male. (After Hirst 
1922) 



Genera 
1. 



Diagnosis: The dorsal shields 
vary in number and shape. Parts 
of the skin are smooth, wrinkled, 
have transverse striations, or are 
scaly. A pair of vertical setae is 
present. The maxillae, parts of the 
legs, or the entire leg or sternal 
formation are transformed into 
clasping organs that enclose a 
single hair of the mammalian 
host. The body is oblong (except 
Myocoptes) and often strongly 
compressed laterally, and has 
vertical setae. There are genital 
suckers (some exceptions) and 
the males have adanal copulatory 
suckers that may be very incon- 
spicuous or even lacking. 



Listrophoriis Pagenstecher, 1861 

Type. Listrophoriis leuchcirti Pagenstecher, 1861 

Alabidocarpiis Ewing, 1929 

Type. Lcihidocarpiis niegcdonyx Trouessart, 1895 



Sarcoptiformes 377 

3. Atopomeliis Trouessart, 1918 

Type. Atopomeliis locusta Trouessart, 1918 

4. AiistrochirusV^omQvsiQy, 1943 

Type. Aiistrochinis qiieenslandiciis Womersley, 1943 

5. Campy lochiriis Trouessart, 1893 

Type. Campy lochiriis chelopiis Trouessart, 1893 

6. Chirodiscoides Hirst, 1917 (Womersley 1943 synonymizes this with 

Campylochirus Trouessart) 
Type. Chirodiscoides caviae Hirst, 1917 

7. Chirodisciis Trouessart and Neumann, 1890 

Type. Chirodisciis amplexans Trouessart and Neumann, 1890 

8. Eiilabidocarpiis Lawrence, 1948 

Type. Labidocarpus compressus Ewing, 1910 

9. Eurychiroides Womersley, 1943 (= Eiiryzonus Trouessart, 1918 

nom. praeocc.) 
Type. Eiiryzonus ventricosus Trouessart, 1918 

10. Labidocarpus Trouessart, 1895 

Type. Labidocarpus rollinati Trouessart, 1895 

11. Listrophoroides Hirst, 1923 

Type. Listrophoroides aethiopicus Hirst, 1923 

12. Marquesania Womersley, 1943 (= Listrophoroides Ferris, 1932 nom. 

praeocc.) 
Type. Listrophoroides expansus Ferris, 1932 

13. Myoco/7r^>y Claparede, 1869 (= CriniscansorVo^^Q, 1887) 
Type. Sarcoptes musculinus Koch, 1844 

14. Neolabidocarpus Gunther, 1942 

Type. Labidocarpus buloloensis Gunther, 1940 

15. Olabidocarpus Lawrence, 1948 

Type. Labidocarpus belsorum van Eyndhoven, 1940 

16. Prolabidocarpus Lawrence, 1948 

Type. Prolabidocarpus canadensis Lawrence, 1948 

17. Schizocarpus Trouessart, 1896 (= Haptosoma Kramer, 1896) 
Type. Schizocarpus mingaudi Trouessart, 1896 

18. Schizocoptes Lawrence, 1944 

Type. Schizocoptes conjugatus Lawrence, 1944 

19. Trichoecius Canestrini, 1899 (= Trichobius Canestrini, 1897 nom. 

praeocc.) 
Type. Myocoptes brevipes Canestrini and Trouessart, 1895 

Discussion: Gunther 1942 divided the group into four subfamilies 
based on the type of clasping organs. Womersley 1943 keys them as 
follows: 



378 Acarology 

Key to the Listrophoridae 

1. Legs I and ii modified as claspers 2 
Legs III and iv modified as claspers Myocoptinae 

Maxillae modified as claspers Listrophorinae 

2. Legs I and ii with caruncles, not highly modified, sometimes with 
accessory claspers Atopomelinae 
Legs I and ii without caruncles, highly modified, without accessory 
claspers Labidocarpinae 

These mites are found in the hair of small to medium-sized mammals 
and only rarely in the feathers of birds {Chirodiscus) . Myocoptes mus- 
culinus (Koch) produces a type of mange on laboratory white mice 
for which the name "Myocoptic mange" has been proposed. This spe- 
cies is common throughout the world. A listrophorid mite likely to be 
encountered is Chirodiscoides caviae Hirst which is attached to the 
dorsal hairs of the guinea pig; the legs of this species are flattened to 
grasp the hairs of the host. Labidocarpus nasicolus Lawrence has been 
collected on the vibrissae on or near the nose leaf of the bat, each 
being attached near the base of one of these tactile hairs. Lawrence 
1938 says: "Like Myobia this mite is unable to move readily from 
place to place on account of the remarkable modifications of its an- 
terior legs. It seems probable therefore that it descends the hair to 
which it is attached to feed on the secretions liberated by the seba- 
ceous glands at its base. The nose leaf of Rhinolophus (bat) itself is 
unusually well supplied with these fat secreting glands, enabling its 
surface to be kept perpetually moist and thus more sensitive to cur- 
rents of air. It is significant that these mites have hitherto been found 
only on the nose-leaved group of bats of the suborder Microchiroptera. 
Hexapod larvae have been observed in the body cavity of the ovigerous 
female of Labidocarpus rollinati and L. nasicolus^ 

References: 

Gunther, C. 1942. Notes on the Listrophoridae (Acarina: Sarcoptoidea). 

Proc. Linn. Soc. N. S. Wales 67(3, 4) : 109-1 10. 
Lawrence, R. F. 1938. A new acarine parasite of bats. Parasitol. 30(3): 

309-313. 
. 1948. Studies on some parasitic mites from Canada and South 

Africa. J. Parasitol. 34(5) :364-379. 
Womersley, H. 1943. Australian species of Listrophoridae Canest. (Aca- 
. rina) with notes on the new genera. Trans. Roy. Soc. South Australia 

67(1):10-19. 



Sarcoptiformes 



379 



Analgesidae Trouessart, 1915 

Figure 306 



Diagnosis: The analgesids are feather 
mites. As a rule, the females lack plates 
on the hysterosoma (exception Mesal- 
ges) . They have an undivided, rounded, 
posterior margin. Legs i and ii usually 
have latero-ventral, triangular, cufflike 
projections. Legs iii or iv, or both, of 
the male are more developed than the 
others and often are highly developed. 



Figiive W6 Megninia columbae Buchholz. 
Venter of male. (After Hirst 1922) 




Genera. 



3. 



10. 



Amdges Nitzsch, 1818 

Type. Analges passerinus Nitzsch, 1818 

A nalgopsis Trouessart, 1919 

Ty^Q. Acarus passerinus \^mn?iQus, 1758 (= DeGeer, 1778) 

Berlesella TiouQSS2LVi, \9\9 

Type. Berlesella alata Trouessart, 1919 

//^m/a/^^5 Trouessart, 1888 

Type. Megninia pappus Trouessart and Neumann, 1888 

//y/7£r«/ge5' Trouessart, 1915 

Type. Megninia magnifica Trouessart, 1895 

Ingrassia Oudemans, 1905 

Type. Megninia veliger Oudemans^ 1904 

Megninia Berlese, 1881, 

Type. Dermaleichus cubitalis Megnin, 1877 

Mesalges TrouQss?iri, 1888 

Type. Dermaleichus abbreviatus Buchholz, 1869 

Metanalges Trouessart, 1919 

Type. Megninia elongata Trouessart, 1886 

N^fl/ge^ Trouessart, 1886 

Type. Nealges poppeiTvouesssiYt, 1886 



380 Acarology 

11. Plesialges TvouQss2ivX, \9\9 

Type. Plesialges tniiuus Trouessart, 1919 

12. Protolges Trouessart, 1885 (= Hartingia Oudemans, 1897) 
Type. Protalges robini Trouessart, 1885 

13. Psoroptoides TxouQSSdin, 1919 

Type. Megninia psoroptopus Trouessart, 1885 

14. Pteralloptes Trouessart, 1884 (= Analloptes Trouessart, 1885) 
Type. Dermaleichiis stelloris Buchholz, 1869 

15. Varchia Oudemans, 1905 

Type. Pteralloptes gambettae Oudemans, 1904 

16. Xolalges Trouessart, 1885 

Type. Xolalges scaurus Trouessart, 1885 

Rejerences: 

Gaud, J. and M. L. Petitot. 1948. Sarcoptides plumicoles des oiseaux du 

Maroc. Ann. de Parasit. 23(1-2) : 35-46. 
. 1948. Sarcoptides plumicoles des oiseaux dTndochine. Ann. de 

Parasit. 23(5-6) : 337-347. 



Dermoglyphidae Megnin and Trouessart, 1883 

{= Falculiferidae Oudemans, 1908; 

Pterolichidae Trouessart, 1915; 

Syringobiidae Berlese, 1907) 

Figures 307-309 

Diagnosis: The dermoglyphids 

are feather mites. Both sexes have 

at least a propodosomal shield 

and often other dorsal plates as 

well. The posterior of the body is 

either round or slightly emargi- 

nate. A pair of vertical setae is 

present on the propodosoma. 

Legs III and iv are often thicker 

than the others and occasionally 

legs t or II or both are much 

thicker than the others. Apodemes 

of legs I and ii are either united or 

end freely. Heteromorphic males 

may be present in which mon- 

„ , . strous deviations from the normal 
Figure 307 Pterolichiis ohtusus Robin. j • , , i 

Dorsum of female. (After Hirst 1922) are to be found in legs IV and the 




Sarcoptiformes 381 

chelicerae (Bdellorhynchus), or in legs i and ii and the chelicerae 
(Falculifer), or in the palpi (Cheiloceras), or in legs iii and iv (Pro- 
tolichus) . 

The families Falculiferidae, Pterolichidae, and Syringobiidae are 
included under the Dermoglyphidae since at the present time charac- 
ters of familial rank cannot be found and, with the characters used by 
Vitzthum, the families are difficult to key out and are not constant in 
structure. 





Figure 308 Falculifer rostratus (Buch- 
holz). Hypopial nymph. (After Hirst 
1922) 

Genera: 



Figure 309 Falculifer rostratus (Buch- 
holz). Venter of male. 



1. Dermoglyphus Megnin, 1877 

Type. Dermaleichus elongatus Megnin, 1877 

2. ^Aias/cMc^/o/? Trouessart and Neumann, 1888 
Type. Dermaleichus landoisii Buchholz, 1869 

3. Anoplonotus Trouessart, 1915 

Type. Pterolichus semaphorus Trouessart, 1886 

4. Avenzoaria Oudemans, 1905 

Type. Dermaleichus totani Canestrini, 1878 

5. Bdellorhynchus TrouesssLTt, 1885 

Type. Bdellorhynchus polymorphus Trouessart, 1885 



382 Acarology 

6. Bonnetella Trouessart, 1934 (= Buchholzia Trouessart, 1915 nom. 

praeocc.) 
Type. Analges fiiscus Nitzsch, 1818 

7. Ceratothrix Trouessart, 1915 

Type. PteroUchus corniger Trouessart and Neumann, 1888 

8. Chauliacia Oudemans, 1905 

Type. PteroUchus securiger Robin, 1877 

9. C/it-Z/oc^/Y/^ Trouessart, 1898 

Type. Cheiloceras cervus Trouessart, 1898 

10. Cheylabis Trouessart, 1885 

Type. Cheylabis latiis Trouessart, 1885 

11. Co/i/mf-Z/fl/V/ Oudemans, 1904 

ly^Q. Dermoglyphus variansTvoxxes^diVi, 1886 

12. Eustathia Oudemans, 1905 

Type. PteroUchus cuUrifer Robin, 1868 

13. Ffl/cM///^/- Railliet, 1896 

Type. Dermaleichus rostratus Buchholz, 1 869 

14. Freyaim Haller, 1877 

Type. Dermaleichus anatinus Koch, 1841 

15. Gabucinia Oudemans, 1905 

Type. PteroUchus delibatus Tobin, 1877 

16. //«//f;7V/ Trouessart and Megnin, 1885 

Type. Freyana (Halleria) hirsutirostris TvouQSsari and Megnin 

17. Kramerella Trouessart, 1915 (= Crameria Haller, 1878 fioni. 

praeocc.) 
Type. Crameria lunulata Haller, 1878 

18. M ichaelichus TrouessavX and Megnin (= Michaelia Trouessart, 1885, 

sed non — Michaelia Berlese, 1884) 
Type. Dermaleichus heteropus Michael, 1881 

19. M/r/-oc/z^/y5 Trouessart, 1915 

Type. Freyana (Microspalax) delicatula Trouessart, 1898 

20. Microspalax Megnin and Trouessart, 1884 

Type. Freyana {Microspalax) manicata Megnin and Trouessart, 1884 

21. Neumanniella Trouessart. 1915 (— Neumannia Trouessart and Neu- 

mann, 1888 nom. praeocc.) 
Type. Neumannia chelifer Trouessart and Neumann, 1888 

22. Oustaletia Trouessart, 1885 

Type. PteroUchus {Oustaletia) pegasus Trouessart, 1885 

23. Paralges Trouessart, 1885 

Type. Paralges pachycnemis Trouessart, 1885 

24. Plutarchia Oudemans, 1904 

Type. Plutarchia chelopus Oudemans, 1904 {partim — Syringobia 
chelopus Trouessart and Neumann, 1888) 



Sarcoptiformes 383 

25. Protolichus Trouessart, 1884 

Type. Pterolichiis {Protolichiis) brachiatus Trouessart, 1884 

26. Protonyssiis Trouessart, 1915 

Type. Protalges larva Trouessart, 1885 

27. Pseiidogiehelia Radford, 1950 (= Giebelia Trouessart, 1915, nom. 

praeocc. ) 
Type. Deriiialeichiis piifftni Buchholz, 1869 

28. P/^'/o/Zc^i/^ Robin, 1868 

Type. Pterolichiis obtiisiis Robin, 1868 

29. Pteronyssus Koh'm,\^6'i 

Type. Pteronyssus striatus Robin, 1877 

30. Pseudalloptes Trouessart and Megnin, 1884 
Type. Pterolichus hisubulatus Robin, 1877 

31. Sammonica Oudemans, 1904 

Type. Syringobia ovalis Trouessart, 1898 

32. Sphaerogastra Trouessart, 1897 

Type. Sphaerogastra thylacodes Trouessart, 1897 

33. Syringobia Trouessart and Neumann, 1888 

Type. Syringobia chelopiis Trouessart and Neumann, 1888 

34. Thecarthra Trouessart, 1896 

Type. Pterolichus theca Megnin and Trouessart, 1884 

35. Xoloptes Canestrini, 1879 

Type. Pterolichus claudicans Robin, 1877 

Discussion: Oudemans 1922 has outlined the life cycle of the feather 
mites as follows. There are two types of eggs, a hard-shelled one and 
a thin-shelled one. The thin-shelled eggs contain larvae while still 
within the mother and thus the female mite may be either ovoviparous 
or viviparous. There is a six-legged larva which hatches from the egg 
to molt into the eight-legged nymph, the protonymph. The proto- 
nymph molts and the deutonymph emerges. The sexes in this stage 
can be distinguished in that the female possesses a copulatory opening. 
Both forms give rise to the eight-legged adults. When mating takes 
place the male always copulates with the female deutonymph. Spur- 
lock and Emlen 1942 have studied the nymphal form of a feather mite 
which they called Hypodectes chapini and which was found in a red- 
shafted flicker, Colaptes cajer collaris, in California. These mites were 
"loosely encysted in the connective tissue surrounding the trachea, and 
to a lesser extent, the esophagus. The greatest concentration was near 
the point of entrance of the trachea into the buccal cavity, but the area 
of infection extended from the lungs to the tongue. No movement was 
visible with the cysts as far as could be determined, and there was no 



384 Acarology 

apparent pathology in the host tissue at the site of infection." In re- 
viewing the Hterature Spurlock and Emlen state the following on 
Falciilijer rostratiis (Buchhoiz): "The normal nymph molts into the 
hypopial stage during adverse environmental conditions, as during the 
molting of birds, etc. The hypopial forms migrate internally through 
the feather follicles or respiratory organs of the bird host and come to 
lie in subcutaneous or tracheal tissue, there to live and grow until such 
times as external conditions become normal when they return to the 
outside and take on their original form. This deviation of the normal 
life cycle is supposed by these authors (i.e., Robin and Megnin) to 
be a means of saving the colony from destruction." 

PteroUchus obtiisus Robin occurs on several species. of birds such 
as fowl and French partridge. P. bicaudatus Gervais is to be found on 
ostriches in South Africa and California. Dermoglyphus elongatus 
Megnin and D. minor Norner are to be found inside the quills of fowls. 

References: 

Oudemans, A. C. 1922. Ueber die metamorphose der vogelbewohnenden 

Acaridiae. Tijdschr. v. Ent. 65:184-191. 
Spurlock, G. M., and J. T. Emlen. 1942. Hypodectes chapini n. sp. (Aca- 

rina) from the red-shafted flicker. J. Parasitol. 28(4) :341-344. 
Vitzthum, H. 1933. Die endoparasitische Deutonymphe von PteroUchus 

nisi. Zeitschrift f. Parasitenkunde 6(2) : 151-169. 

Proctophyllodidae Megnin and Trouessart, 1883 

Figures 310, 311 

Diagnosis: The proctophyllodids are feather mites. Both sexes have 
dorsal and dorso-lateral propodosomal shields, a hysterosomal shield, 
and several other small shields. The rear of the female body is taper- 
ing, bilobate, and has sword-shaped or bristle-like appendages on each 
lobe. The posterior margin of the male is often bilobate, too, and often 
has leaf-shaped appendages. No vertical setae appear on the propo- 
dosoma. Rodlike, distally blunt tactile setae are found on tibiae i and 
II, All tarsi have caruncles. 

Genera: 

1. Proctophyllodes Robin, 1868 

Type. Dermaleichus glandarinus Koch, 1840 

2. Alloptes G. Canestrini, 1879 

Type. Dermaleichus crassipes Canestrini, 1878 



Sarcoptiformes 



385 



Favettea Trouessart, 1915 

Type. Favettea heteroclyta Trouessart, 1915 

Monojoubertia Radford, 1950 (= Joubertia Oudemans, 1905, nom 

praeocc. ) 
Type. Peterodectes microphy litis Robin and Megnin, 1877 
Montesauria Oudemans, 1905 
Type. Pterodectes cylindriciis Robin, 1868 





Figure 310 Trouessartia rosteri Ber- 
lese. Dorsum of male. 



Figure 311 Trouessartia rosteri Ber- 
lese. Dorsum of female. 



6. Pseiidalges Trouessart, 1885 (= Allanalges Trouessart, 1886) 
Type. Pterocolus analgoides Trouessart, 1885 

7. Pterodectes Koh'm, \^6^ 

Type. Pterodectes rutilus Robin, 1868 

8. Pterophagus Megnin, 1 877 

Type. Pterophagus strictus Megnin, 1877 

9. Trouessartia Canestrini, 1899 (= Pterocolus Haller, 1878, nom. 

praeocc.) 
Type. Dermaleichus corvinus Koch, 1840 



386 Acarology 

Discussion: These are feather-inhabiting mites and are similar in 
habits to the Analgesidae and Dermoglyphidae. 

Reference: 

Vitzthum, H. 1929. Acari. Die Tierwelt Mitteleuropas 3(3):1-112. 



CHAPTER VIII 



Orihatei Duges, 1833 



THE gnathosoma is usually concealed within a camerostome. 
Stigma and tracheae may be present, opening into porose areas. 
Pseudostigmatic organs are generally present on the propodosoma. 
The body is usually strongly sclerotized, dark in color, and when not 
thusly armored the skin is leathery. The coxal apodemes are sunk be- 
neath the skin but are still visible, although not as strongly so as in the 
Acaridiae. The tarsi have one to three claws and are without carun- 
cles. The palpi usually have five movable segments. The two sexes are 
similar. Three pairs of genital suckers are present; the males do not 
possess adanal suckers; and both sexes generally have the genital and 
anal openings covered by lidlike shields. 

The Oribatei, although divided into many larger groups by Euro- 
pean workers, can be easily separated into two distinct groups — the 
Aptyctima and the Ptyctima — in that in the former the propodosoma 
is not movably hinged with the hysterosoma, whereas it is hinged in 
the latter group. 

Within the Aptyctima we find several natural groups based on the 
genital-anal plate arrangement, and possession or lack of pteromorphs 
or wings. Because of the complexity and uncertainty of these divisions 
the reader is referred to Vitzthum, Willmann, and Sellnick. A rather 
comprehensive study of these mites^ as a whole will have to be made 
before these characters can be properly weighed and evaluated. 

The oribatid mites, once considered as of taxonomic interest only, 
have gained economic importance owing to the discovery that many 
of them have been found to be hosts of various tapeworms. In studies 
of soil fauna there is an indication that these mites, which constitute a 
high percentage of the fauna, are important factors in promoting soil 
•fertility through breaking down organic matter by digestion, as do the 

387 



388 Acarology 

earthworms. These two factors alone, the second possibly of really 
great importance, are enough to warrant more extensive study of the 
bionomics of this large, soil-inhabiting group. Jacot, in the United 
States, had made a start toward this goal before he died but had ac- 
complished little; Tragardh, in Sweden, in his study of forest soils has 
contributed some knowledge; and Marie Hammer and S. L. Tuxen 
are at present doing extensive work on the soil fauna, especially on 
the oribatid mites, in Denmark. As can be seen, much remains to be 
done. It is in the study of the soil fauna that the sampling funnels — 
Berlese, TuUgren, and others, and their modifications — have come 
into use, and through these one can gain an insight into the tremendous 
amount of material which can be found in the soil. 

Kates and Runkel 1948 have reviewed the literature on the oriba- 
tids as vectors of the sheep tapeworm, Moniezia expansa, and also 
report on the other species of tapeworm which are known to utilize 
the oribatid mites as intermediate hosts. Apparently there are no taxo- 
nomic units of mites that are vectors; rather it appears that the deter- 
mining factor is which species is dominant in the sheep pasture and 
which is able to swallow the eggs of the tapeworm. Many mites are 
present in pastures but are too small to be vectors; other mites capable 
of being the intermediate host under laboratory conditions will be 
found to be forest-humus-inhabiting mites, not pasture forms, and 
therefore of no importance in transmitting the tapeworm. To date, 
mites in the families Galumnidae, Oribatulidae, Carabodidae, Notas- 
pididae, Pelopidae, Liacaridae, and Haplozetidae have been found to 
be vectors of various tapeworms. The species involved will be listed 
under their respective families. This list is by no means to be consid- 
ered complete, but merely an indication of the number of mites which 
will probably be found to be vectors upon future study. 

To obtain a background for the study of the oribatids, it is necessary 
to have available the early papers by H. E. Ewing, which covered the 
taxonomy of these mites in the Illinois region; the various papers by 
A. P. Jacot, which can be found listed in his obituary in the "Florida 
Entomologist," Vol. XXIV, No. 2, pp. 43-47, 1941; the beautifully 
illustrated papers by Frangois Grandjean of France; A. D. Michael's 
two volumes, '^British Oribatidae," Vol. 1, 1881 and Vol. 2, 1883; 
and the two excellent German publications, one by Carl Willmann, 
"Moosmilben oder Oribatiden (Oribatei), Tierwelt Deutschland," 
Vol. 22, pp. 79-200, 1931, and the other by Max Sellnick, 'Tormen- 
kreiss: Hormilben, Oribatei, Die Tierwelt Mitteleuropas," Vol. 3, pp. 



Oribatei 389 

1-42, 1929. There are many other papers in the Hterature which will 
have to be studied before critical work can be done on the group, but 
the above Ust will give a beginner an idea of the group. At the time of 
this writing very little work has been done on the fauna west of the 
Mississippi River and this region remains practically unknown. East- 
ern North America, especially the northeastern region, has been studied 
to a certain extent by A. P. Jacot who found an influx of some Eu- 
ropean species. One of these [for example, Scheloribates laevigatus 
(Koch)] has been reported by Kates and Runkel 1948 from as far 
west as North Dakota. This species is a well-known German one and 
is also to be found in Russia. Thus some care must be taken when 
studying the western forms, and they should be compared with east- 
ern and European species. This holds true for all mites, both free-living 
and parasitic. 

Since, as a whole, very little is known of the habits of the oribatids, 
nothing will be given under the family headings on biology unless defi- 
nitely known. It is at present sufficient to say that they are generally 
soil and debris livers and are also to be found on tree trunks, in moss, 
lichens, and similar habitats, where they feed on the organic matter. 
Hydrozetes is an exception in that it lives in water. 

Because of the complexities of the divisions created by the Euro- 
pean workers (cohorts, phalanges, etc.) the group is here presented as 
a single large unit divided into families only. A few of the families are 
not so distinct as desired and may, in future time, be recombined. In 
a few cases certain families have been suppressed but, as a whole, the 
present family arrangement has been kept, even though morphological 
characters do not always appear to warrant the divisions. 

Key to the Oribatei i 

1. Mouth parts not visible from above; soft- or hard-bodied 2 
Mouths parts visible from above; soft-bodied Palaeacaridae 

2. Prosoma and opisthosoma not hinged together 3 
Prosoma and opisthosoma hinged together (armadillo-like) 32 

3. Genital and anal openings not in common ventral plate; the bound- 
ary separating these openings close behind genital plates, and 
anal opening at posterior end of hysterosoma 4 

Genital and anal openings in common ventral plate 5 

1 Based on keys by Sellnick and Willmann. 



390 Acarology 

4. Hysterosoma cylindrical; genital opening small, far to rear and in 
front of anal opening Eulohmanniidae 

Hysterosoma pouchlike or baglike; genital opening far to front; 
space between anal and genital openings equal to length of anal 
opening Nanhermanniidae 

Genital and anal openings each lying in separate ventral plate 

Epilohmanniidae 

5. Genital and anal opening large, touching each other and covering 
entire length of opisthosoma 6 

Genital and anal opening moderately small, more or less trapezoid 
shape or oval, separated from each other by distinct section of 
ventral plate 13 

6. Genital and anal opening in common, narrow frame 7 

Genital and anal opening not in narrow frame, but in broad, com- 
mon, ventral plate that reaches to lateral margins of hysterosoma 10 

7. Hysterosoma with flat venter and dorsum either flat or weakly 
arched 8 

Hysterosoma cylindrical Lohmanniidae 

8. Dorsum of hysterosoma lightly arched 9 

Dorsum of hysterosoma flat, usually with raised margin or sunken 
dorsal surface Camisiidae 

9. With pseudostigmata and pseudostigmatic organs; with or without 
transverse sutures on hysterosoma Hypochthoniidae 

Without pseudostigmata or pseudostigmatic organs and in their 
place only simple setae; no transverse sutures Malaconothridae 

10. Adults bearing cast skins of immature stages on dorsum 11 

Adults not bearing cast skins on dorsum of hysterosoma which is 
strongly arched Hermanniidae 

11. Without tubelike or other projections on lateral margins of 
hysterosoma 12 

With tubelike or other projections on lateral margin of hystero- 
soma Hermanniellidae 

12. Dorsum of hysterosoma flat or weakly arched; genital plates 
divided by transverse suture Neoliodidae 

Dorsum of hysterosoma flat; body and legs covered by thick layer 
of secretion; genital plates not divided by transverse suture 

Plateremaeidae 



Oribatei 391 

13. Hysterosoma without pteromorphs or wings 14 

Hysterosoma with distinct, although at times small, pteromorphs 
or wings 21 

14. Chelicerae of usual shape — chelate — for chewing 15 
Chelicerae long, narrow, knifelike, toothed on distal end Gustaviidae 

15. Fourth, and all, legs normal, not adapted for jumping 16 

Fourth pair of legs adapted for jumping; in death leg directed 
forward Zetorchestidae 

16. Lateral\and posterior margins of dorsal shield not bent ventrally 17 

Lateral and posterior margins of dorsal shield bent ventrally, so 
that large part of dorsal shield to be seen on ventral side 

Cymbaeremaeidae 

17. Legs III and iv on lateral margins of venter or not far from them 18 

Legs III and iv beneath venter and fairly distant from lateral 
margins Liacaridae 

18. Legs of usual structure, shorter than body or not beadlike; pro- 
podosoma with lamellae-like, ridged, or bladelike prominences 19 

Legs long, usually longer than body, or when not as long then 
constricted in form of beadlike necklace, each segment strikingly 
bulblike, swollen Belbidae 

19. With or without suture between propodosoma and hysterosoma; 
with pseudostigmata and pseudostigmatic organs 20 

Without suture between propodosoma and hysterosoma; no pseu- 
dostigmata or pseudostigmatic organs; no tectopedia ii and in 

Ameronothridae 

20. Dorsum of hysterosoma smooth or weakly punctate; femora i 
and II never with strikingly long petiole Eremaeidae 

Dorsum of hysterosoma usually with strong sculpturing or weak 
punctations; femora i and ii frequently with thin stalk or petiole 
and swollen distally Carabodidae 

21. Pteromorphs not movably hinged 22 
Pteromorphs movably hinged to body 28 

22. Pteromorphs attached to hysterosoma only; not covering large 
portion of propodosoma 23 



392 Acarology 

Pteromorphs attached to both hysterosoma and propodosoma, 
covering pseudostigmata and even pseudostigmatic organs and 
good portion of propodosoma; with small pteromorphs not 
directed ventrally; with two pairs of genital setae Oripodidae 

23. Pteromorphs extending well past anterior margin of hysterosoma 24 
Pteromorphs not extending past anterior margin of hysterosoma 25 

24. Pteromorphs extending anteriorly but not ventrally from place of 
insertion; lamellae may be large but not spectacularly so 

Tenuialidae 

Pteromorphs extending well anteriorly past anterior margin of 
hysterosoma and strongly curving ventrally; lamellae cover pro- 
podosoma Notaspididae 

25. Pteromorphs not large nor curvmg ventrally 26 
Pteromorphs large and curving ventrally; lamellae cover pro- 
podosoma Oribatellidae 

26. Lamellae not covering most of propodosoma; chelicerae normal, 
without processes 27 

Lamellae covering most of propodosoma; fixed chela of chelicerae 
with forward-directed hornlike process Microzetidae 

27. Pteromorphs in one plane only, not curving ventrally; with four 
pairs of genital setae in adults Oribatulidae 

Pteromorphs curving ventrally; with six pairs of genital setae in 
adults Ceratozetidae 

28. Pteromorphs not extending anterior or posterior to line of attach- 
ment (hinge) to body 29 

Pteromorphs extending anteriorly and posteriorly to line of at- 
tachment to body 30 

29. Genital plates with five pairs of setae (occasionally four accord- 
ing to Vitzthum) ; chelicerae normal, strong; interlamellar setae 
normal Haplozetidae 

Genital plates with six pairs of setae; chelicerae (except in Pro- 
pelops) long, slender, with minute shears; interlamellar setae may 
be normal, missing, or spatulate Pelopidae 

30. Lamellae not covering much of propodosoma 31 
Lamellae covering most of propodosoma; genital plates with five 
pairs of setae; anterior pair of circumanal setae next to anterior 
end of anal opening Epactozetidae 



Oribatei 393 

31. Genital plates with six pairs of setae; anterior pair of circumanal 
setae laterad of anal plates Galumnidae 

Genital plates with five pairs of setae; anterior pair of circumanal 
setae anterior to anal plate Parakalummidae 

32. Hysterosoma not segmented ' 33 
Hysterosoma segmented . Protoplophoridae 

33. Genital and anal openings lying in large plate and separated from 
each other Mesoplophoridae 

Genital and anal openings not lying in large plate and touching 
each other Phthiracaridae 

Palaeacaridae Grandjean, 1932 

Figures 312-315 

Diagnosis: These mites have a very thin cuticle without special 
sclerotization. Their body is divided into a propodosoma and a hys- 
terosoma with a neck-shaped constriction between both. The propo- 





Figtme 312 Grandjeanacarus araneola " Figure 313 Acaronychus trdgardhi 
Grandjean. Dorsum of female. Grandjean. Dorsum of female. (After 

(After Grandjean 1932) Grandjean 1932) 

dosoma has five pairs of setae (the rostral, lamellar, interlamellar, exo- 
stigmatic, and angular setae). Pseudostigmatic organs are filiform or 
lanceolate and are inserted into simple, cuplike pseudostigmata. The 
chelicerae are large, uncovered, project far in front of the rostral plate, 
and have dentate chelae adapted for chewing vegetable substances. 



394 A carology 

Composed of five segments, the palpi are simple. The maxillae have 
two pairs of appendages: the exterior maxillary lobes are strongly 
sclerotized, dentate at the tip, and two-segmented; the inner, thin max- 
illary plates have three pairs of setae. The legs are five- or six-seg- 
mented. Transverse sutures and transverse rows of setae may or may 
not be present on the hysterosoma. The respiratory system consists of 
stigmata on the exterior side of the base of the chelicerae and has 
short tracheae (according to Tragardh). 

Although Grandjean 1932 di- 
vided this group into three dis- 
tinct families — the Palaeacaridae, 
Acaronychidae, and Parhypoch- 
thonidae — it is thought best for 
the present to keep these mites in 
one family — the Palaeacaridae — 
with subfamily divisions. Tragardh 
1932 erected a new suborder for 
these, calling it Palaeacariformes; 
Grandjean 1932 argued that these 
mites were primitive oribatids and 





Figure 314 Acaronychus trdgardhi 
Grandjean. Lateral view of female. 
(After Grandjean 1932) 



Figure 315 Parhypochthonius aphidi- 
niis Berlese. Dorsum of female. (After 
Berlese 1904) 



did not constitute a separate group whereas Zakhvatkin 1945, 1946, 
without further amplification, stated that his studies warranted the sub- 
order rank given them by Tragardh. The present classification, that of 
being the most primitive family of oribatids, is used more or less arbi- 
trarily and, as in many cases, final decision will have to await further 
work on the part of the specialists interested in these primitive forms. 



Key to the Palaeacaridae 

With six free leg segments 2 

With five free leg segments; hysterosoma with transverse sutures 
and separated from propodosoma by suture Parhypochthoniinae 



Oribatei 395 

2. Hysterosoma with transverse suture; suture between propodosoma 
and hysterosoma; two or three pairs of genital suckers Palaeacarinae 

Hysterosoma without transverse sutures; no true segmentation be- 
tween propodosoma and hysterosoma; with three pairs of genital 
suckers and pecuhar genital armature of spinelike processes 

Acaronychinae 

Palaeacarinae Grandjean, 1932 

Genera: 

L Palaeacanis TTSiga.rdh, 1932 

Type. Palaeacanis hystricinus Tragardh, 1932 

2. Aphelacarus Grandjean, 1932 

Type. Parhy pocJithoninus acarinus Berlese, 1910 

3. A rcheonothrus Tr'ixgkrdh, 1906 

Type. Archeonothnis natalensis Tragardh, 1906 

4. Beklemishevia Zakhvatkin, 1945 

Type. Beklemishevia galeodiila Zakhvatkin, 1945 

5. Grandjeanacarus Z2iV\\\?L\k\n, 1945 

Type. Palaeacanis araiieola Grandjean, 1932 

6. Trdgdrdhacarus Zakhvatkin, 1945 

Type. Tragdrdhacarus lapshovi Zakhvatkin, 1945 

Acaronychinae Grandjean, 1932 

Genus: 

Acaronychus Grandjean, 1932 

Type. Acaronychus trdgdrdhi Grandjean, 1932 

Parhypochthoniinae Grandjean, 1932 
Genera: 

1. Parhy pochthonius Berlese, 1904 

Type. Parhy pochthonius aphidinus Berlese, 1904 

2. Gehy pochthonius Jsicot, 1936 

Type. Gehy pochthonius rhadamantus Jacot, 1936 

Discussion: These mites are little known and have been seen by only 
a few acarologists. They live in forest soil and debris and will probably 
be found to be more common than suspected when more thorough 
collections are made. 

References: 

Grandjean, F. 1932. Au sujet des Palaeacariformes Tragardh. Bull. Paris 
Mus. d'Hist. Nat. Ser. 2, 4(4) .41 1-426. 



396 



Acarology 



Jacot, A. P. 1936. Some primitive moss-mites of North Carolina. J. Elisha 

Mitchell Sci. Soc. 52(1) :20-26, PI. 1. 
. . 1936. More primitive moss-mites of North Carolina. J. Elisha 

Mitchell Sci. Soc. 52(2) :247-353, PI. 20. 
. 1938. More primitive moss-mites of North Carolina — III. J. 

Elisha Mitchell Sci. Soc. 54(1) :127-137, Pis. 12, 12. 
Tragardh, I. 1932. Palaeacariformes, a new suborder of Acari. Arkiv. for 

Zoologi, 24B(2):l-6. 
Zakhvatkin, A. 1945. On the discovery of Palaeacariformes (Acarina) in 

the U.S.S.R. Comptes Rendus (Doklady) de I'Academie des Sciences 

de rU.S.S.R. 47(9):673-676 (English text). 
. 1945. Etude morphologique sur Beklemishevia galeoduki n. g. 

et n. sp. — representant nouveau des Palaeacariformes (Acarina). 

Moskov. Obshch. Isp. Prirody, Otd. Biol. Biul. (Soc. Nat. de 

Moscou, Sect. Biol. Bui.) an. 116, 50:60-71 (French summary, Rus- 
sian text) . 




Eulohmanniidae Grandjean, 1931 

Figure 316 

Diagnosis: The eulohmanniids are slender, 
elongated mites whose propodosoma and 
hysterosoma are connected by a thin mem- 
brane. The hysterosoma is cylindrical. Gen- 
ital plates are placed far towards the rear 
and are separated from the anal plates by the 
hysterosomal plate suture. 



Figure 316 Eiilohmannia ribagai Berlese. Dor- 
sum of female. (After Berlese 1910) 



Genera: 
1. 



Eiilohmannia Berlese, 1910 (= Arthronothrus Tragardh, 1910) 

Type. Lohmannia {Eiilohmannia) ribagai Berlese, 1910 

Collohmannia Sellnick, 1922 

Type. Collohmannia gigantea Sellnick, 1922 

Perlohmannia Berlese, 1916 

Type. Lohmannia insignis Berlese, 1904 



Oribatei 



397 



Discussion: Collohmannia and Perlohmannia are placed here tenta- 
tively until more critical study can be made. 

Nanhermanniidae Sellnick, 1924 

Figures 317, 318 

Diagnosis: These mites are elongated, narrow, and have a pouchlike 
hysterosoma. Anal plates are placed on the venter at the rear; genital 
plates are located anteriorly and are separated from the anal opening 





Figure 317 Nanhermannia nana (Ni- Figure 318 Nanhermannia elegantiila 

colet). Venter of hysterosoma showing Berlese. Dorsum of female. (After 

division Hne between genital and anal Berlese 1913) 
plates. 

by a suture between the dorsum and the venter of the hysterosoma. 
The suture has moved forward on the venter so as not to include the 
anal opening which actually lies in a ventral portion of the dorsal 
shield. 



Genus: 



Nanhermannia Berlese, 1913 
Type, Nothrus nanus Nicolet, 1855 



398 



Acarology 



Reference: 

Hartman, A. G. 1949. A new species of Nanhermannia with notes on the 
genus. Proc. Ent. Soc. Wash. 51(4) : 169-171. 

Epilohmanniidae Oudemans, 1923 

Figures 319, 320 

Diagnosis: These mites are small and have two ventral plates, one 
behind the other, each with a posterior indentation which encloses the 
genital, or, respectively, the anal plates. There are no lamellae or tec- 





(^' '-^ 




Figure 319 EpUohmannia cylindrica 
(Berlese). Venter of female showing 
divisions of plates. (After Oudemans 
1915) 



Figure 320 EpUohmannia cylindrica 
(Berlese). Venter of larva showing the 
organ of Claparede between coxae i 
and II (see Rhizoglyphus echinopus 
larva). (After Grandjean 1946) 



topedia. The last four segments of the legs are almost equal in length 
and there is one claw. The palpus is two-segmented and the mouth 
parts are hidden from above. The larval form of EpUohmannia cylin- 
drica (Berlese) possesses the Claparede organ. 

Genera: 

1. EpUohmannia Berlese, 1916 {— Lesseria Oudemans, 1916) 
Type. Lohmannia cylindrica Berlese, 1904 

2. Archegozetes GY2Lnd']t2in, \9?)\ 

Type. EpUohmannia (?) magna Sellnick, 1925 



Oribatei 



399 



Lohmanniidae Grandjean, 1931 

Figures 321, 322 

Diagnosis: The lohmanniids have a cyhndrical hysterosoma which is 
broadly attached to the propodosoma. The genital and anal plates ara 
contiguous. The palpi have four movable segments. 





Figure 321 Torpacariis omittens Figure 322 Torpacanis omittens 

Grandjean. Venter of female. (After Grandjean. Dorsum of female. (After 
Grandjean 1950) Grandjean 1950) 



Genera: 

1. Lohmannia Michael, 1898 {— Michaelia Haller, 1884, 

occ. ) 
Type. Michaelia paradoxa Haller, 1884 

2. Annectacarus Grandjean, 1950 

Type. Annectacarus mucronatus Grandjean, 1950 

3. Cryptacarus Grandjean, 1950 

Type. Cryptacarus promecus Grandjean, 1950 

4. Meristacarus Grandjean, 1934 

Type. Meristacarus porcula Grandjean, 1934 

5. Thamnacarus Grandjean, 1950 

Type. Lohmannia deserticola Grandjean, 1934 

6. Torpacarus Grandjean, 1950 

Type. Torpacarus omittens Grandjean, 1950 



nom. prae- 



Discussion: Grandjean 1950 has limited the family to the above gen- 
era, stating that they are an isolated, homogeneous group with primi- 
tive characters. They lack tracheae, lateral-hysterosomal glands, and 
have a gradual development in which the larval, three nymphal, and 
adult stages resemble one another. 



400 

Reference: 
Grandjean, F 



Acarology 



1950. Etude sur les Lohmanniidae (Oribates, Acariens). 
Archiv. Zool. Exper. et Generale 87(2) :95-161. 



Hypochthoniidae Berlese, 1910 

Figures 323-326 

Diagnosis: None, one, or several transverse sutures divide the dor- 
sum of the hysterosoma into several sections. The body is weakly 
sclerotized. The genital plates are usually broader than the anal plates. 





Figure 323 Pterochthoniiis angelus 
(Berlese). Dorsum of female, detail of 
propodosomal seta, palpus, clawlike 
set of ovapositor, and chelicera. 
(After Grandjean 1950) 



Figure 324 Hypochthoniiis riifidus 
var. paucipectinatiis Jacot. Dorsum of 
female. 



Only one egg develops at a time except in Trhypochthonius and Trhy- 
pochthoniellus where four to six eggs may mature simultaneously. 
These two genera have been placed in a distinct subfamily — Trhy- 
pochthoniinae — by Willmann, and into a family by Vitzthum. Grand- 
jean 1946 divided the Hypochthoniidae into the Hypochthoniidae, 
Brachychthoniidae, Cosmochthoniidae, and Sphaerochthoniidae, these 
being based upon the number and location of the transverse sutures; 
in 1950 he erected the family Pterochthoniidae for Pterochthonius 
angelus (Berlese), basing it upon the primitive chelicerae, the reten- 
tion of the preanal segment, the clawlike ovipositor setae, and the 
large, ornate body setae. This is a primitive mite to be found in west- 



Oribatei 



401 



ern Europe and the mountains of Mexico. Sellnick placed all the gen- 
era under one family and his grouping is being retained, although 
future work will probably corroborate Grandjean's findings. 





Figure 325 Cosmochthonius plumatus 
Berlese. Dorsum of female. 



Figure 326 Eniochthoniiis pallidiilus 
(Michael). Ventral plates of female. 
(After Grandjean 1933) 



Genera: 



2. 



1948 



5. 



7. 



9. 



Hypochthomus Koch, 1836 {— Hypochthoniella Berlese, 1910 

— Arthrochthonius Ewing, 1917) 
Type. Hypochthonius rufulus Koch, 1836 
Amnemochthonius Grandjean, 1948 
Type. Amnemochthonius taeniophorus Grandjean, 1948 
Atopochthonius Grandjean, 1948 
Type. Atopochthonius artiodactylus Grandjean, 
Brachychochthonius Jacot, 1938 
Type. Brachychochthonius jugatus Jacot, 1938 
Brachychthonius Berlese, 1910 
Type. Hypochthonius brevis Michael, 1887 
Cosmochthonius Berlese, 1910 
Type. Hypochthonius lanatus Michael, 1887 
Eniochthonius Grandjean, 1933 
Type. Hypochthonius pallidulus Michael, 1887 
Eobrachychthonius Jacot, 1936 
Type. Eobrachychthonius sexnotatus Jacot, 1936 
Eohypochthonius Jacot, 1938 
Type. Hypochthonius gracilis Jacot, 1936 




402 Acarology 

10. Epilohmonnoides JacoX, 1936 

Type. Epilohmcmnoides terrae Jacoi, 1936 

11. Haplochthonius yN'iWmann, 1930 

Type. Haplochthonius simplex Willmann, 1930 

12. Heterochthonius Berlese, 1910 

Type. Cosmochthonius (Heterochthonius) gihhus Berlese, 1910 

13. Malacoangelia Berlese, 1913 

Type. Malacoangelia remigera Berlese, 1910 

14. Poecilochthonius Balogh, 1943 

Type. Brachychthonius italiciis Berlese, 1910 

15. Pterochthonius Berlese, 1913 

Type. Cosmochthonius angehis Berlese, 1910 

16. Sphaeiochthonius Berlese, 1910 

Type. Hypochthonius splendidus Berlese, 1904 

17. Trhypochthoniellus WiWmann, 1928 

Type. Trhypochthoniellus setosus Willmann, 1928 

18. Trhypochthonius Berlese, 1904 (= Tumiclalvus Ewing, 1908) 
Type. Hypochthonius tectorum Berlese, 1896 

References: 

Grandjean, F. 1928. Sur un oribatide pourvu d'yeux. Bull. Soc. Zool. 
France 53(4) : 235-242. 

. 1946. Les Enarthronota (Acariens) 1 serie. Annales Sciences 

Naturelles ser. Botanique et Zoologie, 11 Ser., 8:213-248. 

. 1948. Les Enarthronota (Acariens) 2 serie. Annales Sciences 

Naturelles ser. Botanique et Zoologie, 11 Ser., 10:29-58. 

. 1950. Les Enarthronota (Acariens) 3 serie. Annales Sciences 

Naturelles ser. Botanique et Zoologie, 11 Ser,, 12:85-107. 

Jacot, A. P. See references under Palaeacaridae. 

Womersley, H. 1945. Australian Acarina. The genera Brachychthonius 
Berl. and Cosmochthonius Berl. (Hypochthonidae-Oribatoidea) . Rec- 
ords South Austral. Mus. 8: (2) :219-223. 



Oribatei 



403 



Malaconothridae Berlese, 1916 

Figure 327 

Diagnosis: These mites are generally grayish- 
or yellowish-brown in color. The dorsum of the 
body is slightly convex. There are no true pseu- 
dostigmata or pseudostigmatic organs but there 
is a simple bristle instead. 



Figure 327 Malaconothrus egregia Berlese. Dorsum 
of female. Note lack of pseudostigmatic organs. (After 
Berlese 1905) 



Genera: 

1. Malaconothrus Berlese, 1905 

Type. Nothrus monodactylus Michael, 1888 

2. Mucronothrus Tx'digkvdh, \92>\ 

Type. Mucronothrus rostratus Tragardh, 1931 

3. Trimalaconothrus Berlese, 1916 

Type. Malaconothrus {Trimalaconothrus) indusiatus Berlese, 1916 




Camisiidae Sellnick, 1928 

Figure 328 

Diagnosis: The genital and anal openings are contiguous. Small, scle- 
rotic strips or plates lie close to the genital and 
anal openings; the anal opening is closed by a 
pair of striplike, sclerotic plates. The pseudo- 
stigmatic organs are either funnel- or shell- 
shaped. Usually with raised margins^ the dorsum 
of the hysterosoma is flat. Many of the species 
of Camisia have characteristic elongated proc- 
esses on the posterior margin of the body. 



Figure 328 Camisia segnis (Hermann). Dorsum of fe- 
male and dorsal seta enlarged. (After Grandjean 1936) 




404 
Genera: 



Acarology 



1. Cflmw/^ V, Hey den, 1826 

Type. Notaspis segnis Hermann, 1804 

2. Acronothnis Berlese, 1916 

Type. Nothrus cophinarius Michael, 1907 

3. Heminothrus Berlese, 1913 

Type. Nothrus targionii Berlese, 1885 

4. Nothrus Koch, 1836 (= Angelia Berlese, 

Ewing, 1917) 
Type. Nothrus palustris Koch, 1839 

5. P/afyA2or/zrM5 Berlese, 1913 

Type. Nothrus peltifer Koch, 1839 

6. Uronothrus Berlese, 1913 
Type. Nothrus segnis Koch, 1839 



1885 = Gymnonothrus 



Hermanniidae Sellnick, 1928 

Figures 329-331 




Diagnosis: The hermanniids 
have a strongly convex hystero- 
soma. Their genital and anal 
plates are contiguous in the com- 
mon ventral plate. 



Figure 329 Hermannia gibba (Koch). 
Dorsum of female. 



Genera and subgenera: 

1. Hermannia Nicolet, 1855 

a. Hermannia s. str. 

Type. Nothrus gibbus Koch, 1839 

b. Phyllhermannia Berlese, 1916 

Type. Hermannia phyllophora Michael, 1908 



Oribatei 



405 



Masthermannia Berlese, 1913 

Type. Angelia mammillaris Berlese, 1904 





Figure 330 Hermannia gibba (Koch). 
Showing arrangement of ventral plates. 



Figure 331 Masthermannia mammil- 
laris (Berlese). Showing bizzare struc- 
tures occasionally found in mites. 
(After Berlese 1913) 



Neoliodidae Willmann, 1913 

Figures 332, 333 ■ 

Diagnosis: The lateral and posterior margins of the dorsal shields 
are bent angularly toward the venter so that a considerable portion of 
the dorsal shield lies ventrally. The dorsum of the hysterosoma is com- 
pletely covered with cast skins (which lie one on the other) of the 
young stages. Each flap of the genital opening is divided into two parts 
by a transverse suture. 

Genera: 

1. Neoliodes Berlese, 1888 (= Liodes Heyden, 1826, nom. praeocc.= 

Udetaliodes Jacot, 1929) 
Type. Notaspis theleproctus Hermann, 1804 

2. Embolacarus Sellnick, 1918 (fossil) 

Type. Embolacarus pergratus Sellnick, 1918 (according to Vitzthum 
the systematic position of this genus is uncertain) 

3. Platy liodes Berlese, 1916 

Type. Nothrus doderleinii Berlese, 1883 



406 



Acarology 



4. Poroliodes Grandjean, 1934 

Type. Nothrus theleproctus Michael, 1888 

5. Teleioliodes Grandjean, 1934 

Type. Teleioliodes madininensis Grandjean, 1934 





Figure 332 Teoiiodes madininensis Figure 333 Neoliodes sp. Venter, 

Grandjean. Dorsum of female. (After showing arrangement of ventral plates. 
Grandjean 1934) 



Cymbaeremaeidae Willmann, 1931 

Figures 334, 335 





Figure 334 Cymbaeremaeus Figure 335 Cymbaeremaeiis 

(Scaoheremaeus) marginalis (Banks). {Scapheremaeus) marginalis (Banks). 
Dorsum of female. Venter of female showing arrangement 

of shields and plates. 



Oribatei 407 

Diagnosis: Apterogasterina. The dorsal shield is turned under toward 
the venter so that when it is seen from below a large part of the dorsal 
armor can also be seen. The body is variously sculptured. 

Genera and subgenera: 

1. Cymbaeremaeus Berlese, 1896 

a. Cy mbaeremoeus s. str. 

Type. Eremaeus cymba Nicolet, 1855 

b. Scapheremaeus Berlese, 1910 (= Mulvius Sellnick, 1918, fossil) 
Type. Eremaeus cymba Berlese, 1886 

2. Eremella Berlese, 1913 

Type. Eremella vestita Berlese, 1913 

3. Micreremus Berlese, 1908 

Type. Eremaeus brevipes Michael, 1888 

4. Tectocymba Sellnick, 1918, fossil 
Type. Tectocymba rara Sellnick, 1918 

Belbidae Willmann, 1931 

Figures 336-338 

Diagnosis: Apterogasterina. Their chelic- 

erae are normal as is the dorsal plate 

which does not curve ventrally. Legs iii 

and IV are placed on or near the edge of 

the body. Usually these are large mites 

with legs which are longer than their body; smaller species have legs in 

which the shape of the segments gives a beaded effect. Sometimes they 

carry cast skins of immature stages on the dorsum. 

Genera and subgenera: 

1. Belbaw. Heyden, 1826 

Type. Notaspis corynopus Hermann, 1804 

2. Allodamaeus Banks, 1947 

Type. Allodamaeus ewingi Banks, 1947 

3. Amerus Berlese, 1896 

a. Amerus s. str. 

Type. Belba troisii Berlese, 1883 

b. Neamerus Willmann, 1939 

Type. Amerus {Neamerus) lundbladi WiWmsinn, 1939 

4. Damaeus Koch, 1836 

Type. Damaeus auritus Koch, 1836 




Figure 336 Belba sp. Leg i. 



408 



Acarology 



6. 



Dameobelba Sellnick, 1928 
Type. Oribata mhiiitissimus Sellnick, 1920 
Gymnodamaeus Kulczynski, 1902 
Type. Damaeus bicostatus Koch, 1836 





Figure 337 Belba jacoti Wilson. Dor- 
sum of female without cast skins on 
dorsum. (After Wilson 1936) 



Figure 338 Belba jacoti Wilson. Fe- 
male with cast nymphal skins on back. 
(After Wilson 1936) 



7. Jacotella Banks, 1947 

Type. Gymnodamaeus qiiadricaudicuhis Jacot, 1937 

8. Porobelba Grandjean, 1936 

Type. Oribata spinosus Sellnick, 1920 



Eremaeidae Willmann, 1931 

Figures 339, 340 

Diagnosis: The lateral and posterior margins of the hysterosoma are 
not turned under. Legs in and iv are articulated at the lateral margin 
of the ventral surface or only a short distance from it. The legs are 
shorter than the body and of ordinary structure. Femora i and ii lack 
a conspicuous stalk or projecting scapular angles. The propodosoma 
has ledgelike or leaflike lamellae and the dorsum of the hysterosoma 
is either smooth or weakly punctate. 



Oribatei 



409 



Genera and subgenera: 

1. Eremaeus Koch, 1836 

Type. Eremaeus hepaticus Koch, 1836 

2. Amerobelba Berlese, 1908 

Type. Amerobelba decedens Berlese, 1908 

3. Autogneta Hull, 1916 

Type. Notaspis longilamellata Michael, 1888 





Figure 339 Lucoppia sp. Venter of fe- 
male showing leg attachment. 



Figure 340 Ceratoppia bipilis (Her- 
mann). Dorsum of female. 



4. Caleremaeus Berlese, 1910 

Type. Notaspis monilipes Michael, 1882 

5. Calvoppia Jacot, 1934 

Type. Calvoppia perkinsi Jacot, 1934 

6. Ceratoppia Berlese, 1908 

Type. Notaspis bipilis Hermann^ 1804 

7. Conoppia Berlese, 1908 

Type. Oppia microptera Berlese, 1885 

8. Damaeolus Paoli, 1908 

Type. Damaeosoma aperatum Berlese, 1903 

9. Dampfiella SQWmok, \93>\ 

Type. Dampfiella procera Sellnick, 1931 
10. Dolicheremaeus Jacot, 1938 

Type. Dolicheremaeus rubripedes Jacot, 1938 



410 Acarology 

11. Eremobelba BqyXqsq, \90^ 

Type. Eremaeus leporosus Haller, 1884 

12. Eremulus Berlese, 1908 

a. Eremulus s. str. 

Type. Eremulus flagellifer Berlese, 1908 

b. Epieremulus Berlese, 1916 

Type. Eremulus {Epieremulus) geometrlcus Berlese, 1916 

13. Gradidorsum Sellnick, 1918, fossil 
Type. Gradidorsum asper Sellnick, 1918 

14. Gymnodampia Jacot, 1937 

Type. Amerobelba setata Berlese, 1916 

15. Imparatoppia Jacot, 1934 

Type. Imparatoppia imparata Jacot, 1934 

16. //fl/oz^f ^5 Berlese, 1916 

Type. Notaspis marina Lohmann, 1907 

17. Lawrencoppia Jacot, 1934 

Type. Lawrencoppia mauritius Jacot, 1934 

18. Hydrozetes Berlese, 1902 

Type. Notaspis lacustris Michael, 1882 

19. Licneremaeus Paoli, 1908 

Type. Notaspis licnophorus Michael, 1882 

20. Licnobelba Grandjean, 1931 

Type. Licnobelba alestensis Grandjean, 1931 

21. L/C A7o^am«^M5' Grandjean, 1931 

Type. Licneremaeus undulatus Paoli, 1908 

22. L/c«o//o^^5 Grandjean, 1931 

Type. Licnoliodes andrei Grandjean, 1931 

23. Lucoppia Berlese, 1908 

a. Lucoppia s. str. 

Type. Zetes lucorum Koch, 1840 

b. Phauloppia Berlese, 1908 

Type. Oppia conformis Berlese, 1895 

24. Metrioppia Grandjean, 1931 

Type. Metrioppia helvetica Grandjean, 1931 

25. Nasozetes SeWnick, 1930 

Type. Nasozetes sumatrensis Sellnick, 1930 

26. Oppia Koch, 1836 (= Dameosoma Berlese, 1892 = Amolops Hull, 

1916 = Dissorhina Hull, 1916 = Zetobelba Hull, 1916) 
Type. Oppia nitens Koch, 1836 

27. Oppiella Jacot, 1937 

Type. Dameosoma corrugatum Berlese, 1904 

28. OnT^flmLatreille, 1802 

Type. Acarus geniculatus Linnaeus, 1758 



Oribatei 411 

29. Paraliodes ndiW, 1911 

Type. Paraliodes incurvata Hall, 1911 

30. Oribella Berlese, 1908 

Type. Notaspis pectinata Michael, 1885 

31. Pe/opp/a Sellnick, 1931 

Type. Peloppia serrata Sellnick, 1931 

32. Phyllotegeus BqyXqsq, \9\?> 

Type. Leiosoma palmicinctum Michael, 1883 

33. Polypterozetes Berlese, 1916 

Type. Polyterozetes cherubin Berlese, 1916 

34. Rhynchoribates Grandjean, 1929 

Type. Rhynchoribates rostratus Grandjean, 1929 

35. Strieremaeus Sellnick, 1918, fossil 

Type. Strieremaeus illibatus Sellnick, 1918 

36. Suctobelba Paoli, 1908 

Type. Notaspis trigona Michael, 1888 

37. Siictobelbella Jacot, 1937 

Type. Siictobelbella serratirostrum Jacot, 1937 

38. Suctobelbila Jacot, 1937 

Type. Suctobelbila punctillata Jacot, 1937 

39. Tricheremaeus Berlese, 1908 

Type. Notaspis serrata Michael, 1885 

40. Trizetes Berlese, 1904 

Type. Trizetes pyramidalis Berlese, 1904 

41. Tuberemaeus Sellnick, 1930 

Type. Tuberemaeus singularis Sellnick, 1930 

Peloppia and Metrioppia have been placed into a separate family — 
Peloppiidae Balogh, 1943 — on the basis of the long, slender chelicerae 
such as is to be found in many of the Pelopidae. The present, more 
conservative arrangement is followed here. 

References: 

Grandjean, F. 1948. Sur les Hydrozetes (Acariens) de I'Europe Occiden- 
tale. Bull. Paris Mus. d'Hist. Nat., Ser. 2, 20(4) :328-335. 

Newell, I. M. 1945. Hydrozetes Berlese (Acari, Oribatoidea) : The occur- 
rence of the genus in North America, and the phenomenon of levita- 
tion. Trans. Conn. Acad. Arts and Sci. 36:253-275. 

Strenzke, K. 1950. Bestimmungstabelle der holsteinischen Suctobelba- 
Arten (Acarina: Oribatei). Archiv. fiir Hydrobiologie 44:340-343. 



412 



Acarology 



Carabodidae Willmann, 1931 

Figure 341 




Figure 341 Cepheiis mirabiloides 
Jacot. Dorsum of female. 



Diagnosis: The lateral and poste- 
rior margins of the hysterosoma 
are not turned under ventrally. Usu- 
ally the dorsum of the hysterosoma 
is coarsely sculptured or at least dis- 
tinctly punctate. Legs iii and iv are 
articulated at the lateral margin 
of the ventral surface or very close 
to it. The legs are of normal struc- 
ture and are shorter than the body. 
Femora i and ii frequently have a 
thin stalk and are greatly swollen 
distally. The propodosoma has 
lamellae-like protuberances, ledges, 
or small leaves or shelves. 



Genera and subgenera: 

1. Carabodes Koch, 1836 

a. Carabodes s. sir. 

Type. Carabodes coriaceus Koch, 1836 

b. Carabocepheus Berlese, 1910 

Type. Carabodes {Carabocepheus) lounsburyi Berlese, 1910 

c. Otocepheus Berlese, 1904 

Type. Carabodes {Otocepheus) longior Berlese, 1904 

2. Carabodoides Jacot, 1937 

Type. Carabodoides saccharomycetoides Jacot, 1937 

3. Cepheus Koch, 1836 (= Tegeocranus Nicolet, 1855) 

a. Cepheus s. str. 

Type. Cepheus latus Koch, 1836 

b. Chaunoproctus Pearse, 1906 

Type. Chaunoproctus canceilatus Pearse, 1906 (poorly described 
and position uncertain) 

c. Microtegeus Berlese, 1916 

Type. Tegeocranus {Microtegeus) undulatus Berlese, 1916 

d. Oribatodes "Qdinks, 1895 

Type. Oribatodes mirabilis Banks, 1895 

e. Protocepheus Jacot, 1928 

Type. Tegeocranus hericius Michael, 1887 



Oribatei 413 

4. Cerocepheus Tragardh, 1931 

Type. Cerocepheus mirabilis Tragardh, 1931 

5. Charassobates Grandjean, 1929 

Type. Charassobates cavernosus Grandjean, 1929 

6. Eremaeozetes Berlese, 1913 

Type. Eremaeozetes tuberculatus Berlese, 1913 

7. Eremobodes Jacot, 1937 

Type, Eremobodes pectinatus Jacot, 1937 

8. Eupterotegaeus Berlese, 1916 

Type. Tegeocramis ornatissimus Berlese, 1908 

9. Eutegaeus Berlese, 1916 

Type. Oribata bostocki Michael, 1908 

10. N eocepheus WiWmann, \936 

Type. Neocepheus hummelincki Willmann, 1936 

11. N iphocepheus BdiXogh, \9A2) 

Type. Cepheus nivalis Schweizer, 1922 

12. Ommatocepheus Berlese, 1913 

Type. Cepheus ocellatus Michael, 1882 

13. Passalozetes Grandjean, 1932 

Type. Passalozetes africanus Grandjean, 1932 

14. Plategeocranus Sellnick, 1918, fossil 
Type. Nothrus sulcatus Karsch, 1884 

15. Pseudocepheus Jacot, \92S 

Type. Cepheus vulgaris Nicolet, 1855 

16. Scutoribates Sellnick, 1918, fossil 

Type. Scutoribates perornatus Sellnick, 1918 

17. Scutovertex Michael, 1879 

Type. Scutovertex sculptus Michael, 1879 

18. Tectocepheus Berlese, 1913 

Type. Tegeocranus velatus Michael, 1880 

19. Tegeocranellus Berlese, 1913 

Type. Tegeocranus laevis Berlese, 1905 

20. TnY^^^M^ Berlese, 1913 

Type. Cepheus bifidatus Nicolet, 1855 

21. Xenillus Robineau-Desvoidy, 1839 (= Cepheus Nicolet, 1855 = 

Banksia Voigts and Oudemans, 1905) 
Type. Notaspis tegeocranus Hermann, 1804 {= Xenillus clypeator 
Robineau-Desvoidy, 1839) 

Discussion: Several species of Carabodidae are known to be vectors 
of tapeworms. They are Scutovertex minutus, vector of Bertiella stu- 
deri, Cittotaenia ctenoides, and C. denticulata in Germany; Xenillus 
tegeocranus, vector of Cittotaenia ctenoides and C. denticulata in Ger- 



414 



Acarology 



many; Cepheus cepheijonnis, vector of C. ctenoides and C. denticulata 
in Germany; and Carabodidae sp., vector of Anoplocephala perjoliata 
in the U.S.S.R. 




Ameronothridae Willmann, 1931 

Figure 342 

Diagnosis: A sclerotized formation bridges the pro- 
podosoma and the hysterosoma and no true dividing 
suture is present. The skin is leather-hke. There are 
no pseudostigmata, sensory setae, or tectopodia ii 
and III. 



Figure 342 Ameronothnis schneideri (Oudemans). Dorsum 
of female showing lack of suture between propodosoma and 
hysterosoma. (After Oudemans 1905) 



Genus: 

Ameronothnis Berlese, 1896 

a. Ameronothrus s. str. 

Type. Eremaeus Uneatus Thorell, 1871 

b. Hygroribates isLCOi, 1934 

Type. Nothrus (?) nuiriniis Banks, 1896 

Discussion: The species belonging to this genus live close to the 
seashore, usually in the tidal zone. A few are known from Europe. 
Ameronothnis {Hygroribates) marinus (Banks) was found on rocks 
in the tidal zone at Sea Cliff, N. Y. Jacot 1934 subsequently found it 
in restricted areas along the New York coast and Grandjean 1947 
collected it on the French coast. Jacot states: "it is evident that this 
species is distinctly marine though mostly restricted to estuaries and 
harbors, i.e., where there is not too much sand scour, and thus where 
growths of films of unicellular algae may develop. It would therefore 
not be expected on the exposed headlands between the bays where 
algal coated rocks are rare or absent. I also suspect that it would be 
rare or absent where rocks are without crannies and fissures. The 
rougher the rock (as schist) the better. Another factor limiting the 
spread of the species is that of viviparity. This means that there are 



Oribatei 



415 



no eggs for dissemination by water currents, but that the young are 
born on the parental stone." 

The figure shown is from Oudemans and although lacking in details 
it does illustrate the family characters. Jacot 1934 gives more detailed 
studies for the North American form but no general drawing. 

References: 

Grandjean, F. 1947. Observations sur les Oribates (17'^ serie). Bull. d'Hist. 

Nat. Ser. 2, 19(2) : 165-172. 
Jacot, A. P. 1934. An introduced moss mite in America. J. N. Y. Ent. 

Soc. 42:329-337. 



Hermanniellidae Grandjean, 1934 

Figures 343-345 

Diagnosis: These mites have a 
small tube which contains the 
mouth of the oil gland projecting 
forward on each side of the opis- 
thosoma. If this tube is lacking a 
strong sclerotized leaflike or wart- 
like outgrowth appears in its 
place. 





Figure 343 Plasmobates pagoda 
Grandjean. Female carrying cast skins 
on back and with secretions on legs. 
(After Grandjean 1929) 



Figure 344 Plasmobates pagoda 
Grandjean. Female with cast skins and 
secretions removed. (After Grandjean 
1929) 



Figure 34^ Plasmobates pagoda 
Grandjean. Chelicera. (After Grand- 
jean 1929) 



416 
Genera: 



Acarology 



1. 



3. 



Hermanniella Berlese, 1908 

Type. Hermannia granulata Nicolet, 1855 

Plasmobates Grandjean, 1929 

Type. Plasmobates pagoda Grandjean, 1929 

Solenozetes Grandjean, 1931 

Type. Plasmobates cribratiis Grandjean, 1929 




Figure 346 Platere- 
maeiis vestitus Tra- 
gardh. Showing articu- 
lation between tibia 
and tarsus iv, femur 
and genu iii, and genu 
and tibia iii. (After 
Tragardh 1931) 



Plateremaeidae Tragardh, 1931 

Figures 346-348 

Diagnosis: The hysterosoma is flat and is cov- 
ered with four concentrically arranged skins 
(one larval and three nymphal exuviae). The 
body and legs are covered with a thick secretion. 
Terminal ends of the femur, genu, and tibia are 
narrow, articulating in the sockets of the genu, 
tibia, and tarsus respectively. Three claws ap- 
pear on the tip of the small peduncle. 



Genus: 

P later emaeus Berlese, 1908 

Type. Damaeus ornatissimus Berlese, 1888 





Figure 347 Plateremaeus vestitus Tra- 
gardh. Dorsum of female. (After Tra- 
gardh 1931) 



Figure 348 Plateremaeus vestitus Tra- 
gardh. Venter of female. (After Tra- 
gardh 1931) 



Reference: 

Tragardh, I. 1931. Acarina from the Juan Fernandez Islands. The Natural 
History of Juan Fernandez and Easter Islands, III. 553-628. 



Oribatei 



417 



Liacaridae Willmann, 1931 

Figures 349, 350 

Diagnosis: Lateral and posterior margins of the hysterosoma are not 
bent ventrally. Legs in and iv are located ventrally, usually far re- 
moved from th^ lateral margins. 





Figure 349 Cultroribula divergens 
Jacot. Dorsum of female. 



Genera: 



Figure 350 Liacarus coracinus (Koch). 
Venter of female showing coxal at- 
tachments. 



1. Liacarus Michael, 1898 (= Leiosoma Nicolet, 1855, nom. praeocc.) 
Type. Oribata nitens Gervais, 1844 

2. Adoristes Hull, 1916 

Type. Oribates ovatus Koch, 1840 

3. AstegistesYhiW, 1916 (= Cultrozetes Sellnick, 1922) 

Type. Acarus muscorum Scopoli, 1763 (= Zetes pilosus Koch, 1840) 

4. Cultroribula Berlese, 1908 

Type. Notaspis juncta Michael, 1885 

Discussion: Three species belonging to this family are known to be 
vectors of various tapeworms. Liacarus coracinus (Koch) is the inter- 
mediate host of Cittotaenia ctenoides and C. denticulata in Germany; 
Adoristes ovatus (Koch) is the intermediate host of a Moniezia sp. in 
Russia; and a Liacarus sp. is the intermediate host of Anoplocephala 
perfoliata in Russia. 



418 



Acarology 



Zetorchestidae Michael, 1898 

Figures 351, 352 

Diagnosis: Leg iv is adapted for jumping. This leg is directed for- 
ward when the mite is dead. There are no pteromorphs. 





Figure 351 Zetorchestes micronychus 
Berlese. Dorsum of female. (After 
Berlese 1883) 

Genera: 



Figure 352 Zetorchestes micronychus 
Berlese. Venter of female showing leg 
IV arrangement. (After Berlese 1883) 



1. Zetorchestes BerlQse, ISSS 

Type. Carabodes micronychus Berlese, 1883 

2. Zetorchella Berlese, 1916 

Type. Zetorchella pedestris Berlese, 1916 




Gustaviidae Willmann, 1931 

Figures 353, 354 

Diagnosis: The chelicerae are 
long, narrow, knifehke, and saw- 
hke on the distal end. There are 
no pteromorphs. 



u. 



Figure 353 Gustavia microcephala 
(Nicolet). Dorsum of female. (After 
Berlese 1884) 



Figure 354 Gustavia microcephala 
(Nicolet). Chelicera. (After Berlese 
1884) 



Oribatei 



419 



Genus: 

Gustavia Kramer, 1879 (= Serrarius Michael, 1883) 
Type. Leiosoma microcephala Nicolet, 1855 (= Gustavia sol Kra- 
mer, 1879) 

Oripodidae Jacot, 1925 

Figure 355 

Diagnosis: These mites belong 
in the Pterogasterina. Pteromorphs 
are strongly developed anteriorly 
and combined with each other 
along the anterior edge of the opis- 
thosoma. A coalesced portion of 
the pteromorphs forms a bridge 
over the propodosoma and covers 
the basal part, or all, of the pseu- 
dostigmatic setae and interlamellar 
setae; this bridge may or may not 
be coalesced with propodosoma. 
Two or three pairs of genital setae 
may be present. 

Figure 355 Oripoda elongata Banks. 
Dorsum of female. 




Genera 
1. 



4. 



Oripoda Banks, 1904 

Type. Oripoda elongata Banks, 1904 

Cryptoribatula Jacot, 1934 

Type. Cryptoribatula taishanensis Jacot, 1934 

Gymnobates Banks, 1902 

Type. Gymnobates glaber Banks, 1902 

Jurabates Jacot, 1929 

Type. Oribata pseudofusiger Schweizer, 1922 



Reference: 

Banks, N. 1904. A treatise on the Acarina, or mites. Proc. U. S. Nat. Mus. 
28(1382):71. 



420 



Acarology 



Tenuialidae Jacot, 1929 

Figure 356 




Diagnosis: The chelicerae are 
broad with strong shears. The 
lamellae are not especially devel- 
oped. Prolonged anteriorly as 
plates the pteromorphs extend the 
length of the opisthosoma without 
interruptions. Jacot's conception 
of the pteromorphs places this 
family into the Pterogasterina. 



Figure 356 Tenuiala mida Ewing. 
Dorsum of female, legs omitted. 



Genera: 

1. Tenuiala Ewing, 1913 

Type. Tenuiala nuda Ewing, 1913 

2. Hafenrefferia Oudemans, 1906 
Type. Oribates gilvipes Koch, 1 840 



Oribatulidae Jacot, 1929 

(= Scheloribatidae Grandjean, 1933) 

Figures 357, 358 

Diagnosis: This family belongs with the Pterogasterina. The ptero- 
morphs lie in one plane only and do not bend ventrally to protect the 
legs. When seen from above the anterior edge of the pteromorph 
curves backward. Each genital plate has four setae (an exception is 
an undescribed species from Panama, which has only the two anterior 
setae left on each plate) . 

Grandjean 1933 created the family Scheloribatidae for those mites 
which differed in the anal setal formula in the immature forms in having 
0-2-3-4-4 in the larval, proto-, deuto-, tritonymphal, and adult stages. 
Oribatulidae has one seta in the larval stage. When the two groups are 



Oribatei 



421 



considered side by side it is difficult to separate them and so the two 
are included as one unit here. 




Figure 357 Protoschelobates seghettii Figure 358 Oribatiila mimita (Ewing). 

Runkel and Kates. Anterior dorsal Dorsum of female. 

portion of female showing ptero- 

morphs, pseudostigma and pseudostig- 

matic organs, lamellae, and setal 

arrangement. 

Genera and subgenera: 

1. On7>flm/« Berlese, 1 896 

a. Oribatiila s. str. 

Type. Notaspis tibialis Nicolet, 1855 

b. Zygoribatula Berlese, 1916 (= Neoribatula Ewing, 1917) 
Type. Oribatula connexa Berlese, 1916 

c. Hemileius Berlese, 1916 

Type. Protoribates (Scheloribates) initialis Berlese, 1908 

2. Cardioribates ]acot, \934 

Type. Oribata oriformis Pearse, 1910 

3. Drymobates Grandjean, 1930 

Type. Drymobates silvicola Grandjean, 1930 

4. Dry mobatoides Jsicot, \936 

Type. Drymobatoides mauritius Jacot, 1936 

5. Eporibatula Sellnick, 1928 

Type. Eremaeus rauschensis Sellnick, 1928 

6. Exoribatula Jacot, 1936 

Type. Exoribatula biundatus Jacot, 1936 

7. Liebstadia Oudemans, 1906 

Type. Notaspis similis Michael, 1888 



422 Acarology 

8. Protoschelobates J acoi, 1934 

Type. Miircia insularis Oudemans, 1917 

9. Schelohbates Berlese, 1908 

a. Scheloribates s. str. 

Type. Zetes latipes Koch, 1844 

b. Paraschelobates J?LCOt, 1934 

Type. Scheloribates (Paraschelobates) mum fordi J acot, 1934 

10. Styloribates Jacot, \934 

Type. Styloribates pect'mcitus Jacot, 1934 

11. U nguizetes SeWmc}^, \925 

Type. Oribates sphaerula Berlese, 1 905 

12. ZetomimusUu\\,\9\6 

Type. Oribata furcata Warburton and Pearse, 1905 

13. Zetomotrichus Grandjean, 1934 

Type. Zetomotrichus lacrimans Grandjean, 1934 

Discussion: In the family Oribatulidae, Scheloribates laevigatas 
(Koch) is the principal vector of the various tapeworms. To date, four 
other species are also involved. S. laevigatas is the intermediate host 
of Moniezia expansa in the United States and Russia; of M. benedeni 
in Russia; of Bertiella studeri, Cittotaenia ctenoides, and C. denticulata 
in Germany; and of Anoplocephala perfoliata, A. magna and Thysa- 
niezia giardi in Russia. Scheloribates latipes (Koch) is the interme- 
diate host of Anoplocephala perfoliata and Thysaniezia giardi in 
Russia. Protoschelobates seghettii Runkel and Kates and Oribatula 
minuta (Ewing) are intermediate hosts of Moniezia expansa in the 
United States. Liebstadia similis (Michael) is the vector of Cittotaenia 
ctenoides in Germany. Kates and Runkel 1948 give an excellent review 
of the biology and distributions of the oribatid mites which are vectors 
of the tapeworms and their work should be consulted for further details. 

References: 

Grandjean, F. 1933. Etude sur le developpement des Oribates. Bull. Soc. 
Zool. France 58(1) :30-61. 

Kates, K. C. and C. E. Runkel. 1948. Observations on oribatid mite vectors 
of Moniezia expansa on pastures, with a report of several new vectors 
from the United States. Proc. Helminth. Soc. Wash. 15(1): 18-33. 



Oribatei 



423 



Ceratozetidae Jacot, 1925 

Figure 359 



Diagnosis: The ceratozetids be- 
long with the Pterogasterina. They 
have small pteromorphs which do 
not project beyond the anterior 
portion of the opisthosoma. The 
inner margin of the lamellae is 
fastened to the propodosoma and 
the anterior portion projects free- 
ly. There may or may not be trans- 
lamellae. Genital plates have six 
pairs of setae. 




Figure 359 Jugatala tuberosa Ewing. 
Dorsum of female. 



Genera and subgenera: 



1. 



1908 



1884 



7. 



Ceratozetes Berlese, 

a. Ceratozetes s. str. 
Type. Oribata gracilis Michael, 

b. Allozetes BqvXqsq, 1913 

Type. Ceratozetes (Allozetes) pusillus Berlese, 1913 
Alloribates Banks, 1947 
Type. Alloribates singularis Banks, 1947 
Balzania Jacot, 1929 

Type. Oribata microptera Canestrini, 1896 
Banksinus Jacot, 1938 
Type. Oribata arborea Banks, 1895 
Calyptozetes Thor, 1929 
Type. Oribata sarekensis Tragar^h, 1910 
Chamobates Hull, 1916 
Type. Oribata cuspidata Michael, 1884 
Diapterobates Grandjean, 1936 

Type. Sphaerozetes {Trichoribates) numerosus Sellnick, 1924 
Edwardzetes BqvXq^q, 1914 
Type. Oribata edwardsii Nicolet, 1855 
Frischia Oudemans, 1915 
Type. Frischia elongata Oudemans, 1915 



424 Acarology 

10. Globozetes SeWnick, 1928 

Type. Globozetes longipilus Sellnick, 1928 

11. //«mmma Sellnick, 1944 

Type. Hammeria groenlandica Sellnick, 1944 

12. Humerobates StWmck, \928 

Type. Notaspis humeralis Hermann, 1804 

13. lugoribates Sellnick, 1944 

Type, lugoribates gracilis Sellnick, 1944 

14. Jugatala Ewing, 1913 

Type. Jugatala tuberosa Ewing, 1913 

15. Limnozetes Hull, 1916 

a. Limnozetes s. str. 

Type. Acarus ciliatus Schrank, 1803 (= Oribata sphagni Michael, 
1884) 

b. Mycobates HuW, 1916 

Type. Oribata parmeliae Michael, 1884 

16. Melanozetes Hull, 1916 

Type. Oribates mollicomus Koch, 1840 

17. Minunthozetes Hull, 1916 

Type. Zetes simirufus Koch, 1840 (= Oribata fusigera Michael, 
1884) 

18. Mochlozetes Grandjean, 1930 

Type. Mochlozetes penetrabilis Grandjean, 1930 

19. Nesiotizetes Jacot, 1934 

Type. Nesiotizetes adamsoni Jacot, 1934 

20. OrmriMrc/fl Thor, 1930 

Type. Oromurcia bicuspidata Thor, 1930 

21. Propeschelobates Jacot, 1936 
Type. Oribata albida Ewing, 1907 

22. Sphaerobates Sellnick, 1928 

Type. Sphaerozetes (?) gratus Sellnick, 1921 

23. Sphaerozetes Berlese, 1885 (= Euzetes Berlese, 1908) 
Type. Oribates orbicularis Koch, 1836 

24. Storkania Jdicoi, \929 

Type. Oribata simplex Storkan, 1925 

25. SvalbardiaJhov, 1930 

Type. Svalbardia paludicola Thor, 1930 

26. Tegeozetes Berlese, 1913 

Type. Tegeozetes tunicatus Berlese, 1913 

27. Terrazetes iacot, \936 

Type. Oribates sphaerula Berlese, 1905 

28. Trachyoribates Berlese, 1908 
a. Trachyoribates s. str. 

Type. Oribates ampulla Berlese, 1904 



Oribatei 



425 



b. ludoribates Jacot, 1929 

Type. Protoribates punctulatus Sellnick, 1925 
29. Trichoribates Berlese, 1910 

a. Trichoribates s. str. 

Type. Miircia trimaculata Koch, 1836 

b. Sphaerozetella Jacot, 1929 

Type. Oribates orbicularis Berlese, 1883 {non C. L. Koch 1836) 

Discussion: Trichoribates incisellus (Kramer) is known to be the 
vector of Cittotaenia ctenoides in Germany. 

References: 

Hammer, Marie. 1944. Studies on the oribatids and collemboles of Green- 
land. Meddelelser om Gronland 141(3) : 1-210. 

. 1946. The zoology of East Greenland. Meddelelser om Gronland 

122(1) :l-39. 



Oribatellidae Jacot, 1925 

Figure 360 



Diagnosis: This family also be- 
longs with the Pterogasterina. The 
pteromorphs do not extend an- 
teriorly past the opisthosoma. The 
lamellae are attached only by their 
rear margin to the propodosoma 
and as a rule they are large, cov- 
ering a considerable part of the 
propodosoma. Many species are 
striking in appearance. 



Figure 360 Oribatella magniseta 
Ewing. Dorsum of female. 



Genera and subgenera: 

1. Oribatella Bdiuks, \^95 

Type. Oribatella quadridentata Banks, 1895 

2. Anachipteria Grandjean, 1932 

Type. Anachipteria deficiens Grandjean, 1932 




426 



A carology 



3. Joelia Oudemans, 1906 (= Coggiella Berlese, 1916) 
Type. Oribates fiorii Coggi, 1898 

4. Tectoribates Berlese, 1910 

a. Tectoribates s. str. 

Type. Oribata tecta Michael, 1883 

b. U nduloribates Balogh, 1943 

Type. Tectoribates undulatiis Berlese, 1915 



Microzetidae Grandjean, 1936 

Figures 361 , 362 



Diagnosis: These mites are in- 
cluded in the Pterogasterina. Their 
chelicerae have a forward-directed 
horn dorsally on the fixed chela. 
Tectopedium i has a large leaf or 
plate which is a continuation of 
the side wall of the propodosoma. 




Figure 361 Phylacozetes membranu- 
lifer Grandjean. Cheliceral tip show- 
ing horn. (After Grandjean 1936) 




Figure 362 Microzetes appalachicola 
Jacot. Dorsum of female. 



The free margin of the tectopedium is of a complicated form with 
large flaps separated from one another by deep incisions; these flaps 
are so rolled that the tectopedium is convexly arched on the line of 
the body axis. The lamellae are always very large, hinged, or joined 
at the base and are not connected with one another; they can be of 
various shapes and can be folded lengthwise. The legs can be with- 
drawn under the lamellae and into these folds if the mite takes a posi- 
tion of protection. From the paraxial side of the lamellae arises a 
membranous flap which may be simple, harpoon-like, or have strong 
teeth. The podosoma and opisthosoma are separated ventrally by a 
broad, dark-colored band, a thickening of apodeme iv; above this can 
be seen a fine transverse suture which joins the anterior lateral corner 
of the genital opening with the sclerotized area surrounding the leg. 
The podosoma is larger than the opisthosoma. 



Oribatei 



427 



Genera: 
1. 



2. 



4. 



Microzetes Berlese, 1913 

Type. Sphaerozetes mirandus Berlese, 1908 

Acaroceras Grandjean, 1936 

Type. Acaroceras odontotus Grandjean, 1936 

NeUacarus Grandjean, 1936 

Type. NeUacarus petrocoriensis Grandjean, 1936 

Phylacozetes Grandjean, 1936 

Type. Phylacozetes membranulifer Grandjean, 1936 



Reference: 
Grandjean, F 



1936. Les Microzetidae n. fam. (Oribates). Bull. Soc. Zool. 
de France 61(2):60-93. 



Notaspididae Oudemans, 1900 

Figure 363 

Diagnosis: Belonging with the Pterogasterina 
these mites have pteromorphs with an anteriorly 
projecting point which reaches almost to the tip 
of the rostrum. Lamellae, which cover almost the 
entire propodosoma, are hinged posteriorly and 
are attached to each other in a small central area. 



Figure 363 Notaspis magnus Sellnick. Dorsum of female. 




Genera: 
1 



3. 



4. 



Notaspis Hermann, 1804 (= Achipteria Berlese, 1885) 

Type. Acarus coleoptratus Linnaeus, 1758 

Achipterina Berlese, 1916 

Type. Achipteria {Achipterina) oribatelloides Berlese, 1916 

Cerachipteria Grandjean, 1935 

Type. Cerachipteria digitata Grandjean, 1935 

Fuscozetes Sellnick, 1928 

Type. Oribata fuscipes Koch, 1 844 



428 Acarology 

Discussion: Notaspis coleoptratus (L.) is a vector of Bertiella stu- 
deri and Cittotaenia ctenoides in Germany, whereas Achipteria {No- 
taspis) sp. is a vector of Anoplocephala perjoliata in Russia. 

Haplozetidae Grandjean, 1936 

Figure 364 

Diagnosis: The haplozetids have 
movable, hinged pteromorphs. 
Tectopedium iv is lengthened by 
a leaflike extension. The genital 
plates have five pairs of setae. 
Grandjean 1936 says there are 
occasionally four pairs of genital 
setae in certain species. 



Figure 364 Peloribates curtipilus 
Jacot. Dorsum of female. 



Genera: 

1. Haplozetes V^'\\\m2inn, \93i5 

Type. Peloribates vindobonensis Willmann, 1935 

2. Neogymnobates Ewing, 1917 

Type. Oribata multipilosa Ewing, 1907 

3. Peloribates Berlese, 1908 (= Parazetes Willmann, 1930 = Eurypara- 

zetes Radford, 1950) 
Type. Oribata peloptoides Berlese, 1888 

4. Protoribates Berlese, 1908 

Type. Oribata monodactyla Haller, 1884 

5. Rostrozetes SQ\\mc\., \925 

Type, Rostrozetes foveolatus Sellnick, 1925 

6. Xylobates ]2iC0i, 1919 

Type. Oribata lophothrichus Berlese, 1904 

Discussion: A single species, Peloribates curtipilus Jacot, has been 
found as a vector of the sheep tapeworm, Moniezia expansa. 




Reference: 

Grandjean, F. 1936. Observations sur les Oribates (10 serie) 
Mus. d'Hist. Nat. Ser. 2, 8(3) : 246-249. 



Bull. Paris 



Oribatei 



429 



Pelopidae Ewing, 1917 

Figures 365, 366 

Diagnosis: Classed with the Pterogasterina the pelopids have large, 
movable, hinged pteromorphs which reach out anteriorly but not pos- 
teriorly over the line of attachment (except in Peloptulus and Galum- 
nella where the posterior end is drawn out to a sharp point). The 
middle part of the anterior margin of the hysterosoma (between ptero- 
morphs) reaches out anteriorly over the borderline between the pro- 



IV 




Figure 365 Pelops sylvesiris Jacot. 
Chelicera and dorsum of female. 



Figure 366 Lepidozetes singiilaris Ber- 
lese. Female. 



podosoma and the hysterosoma, sometimes extending further than the 
anterior end of the pteromorphs. Interlamellar setae are either spatula- 
like {Pelops, Eupelops, Tectopelops, Parapelops) , or normally hair- 
like (Peloptulus, Pelopsis, Propelops), or lacking (Galumnella, Gal- 
umnopsis). The chelicerae are broad at the base and suddenly narrow 
to make a long, slender segment with minute shears (except in Pro- 
pelops which has normal chelicerae). There are six pairs of genital 
setae. 

Genera and subgenera: 

1. Pelops Koch, 1836 

Type. Notaspis hirsutus Koch, 1836 

2. Eupelops Ewing, 1917 

Type. Pelops uraceus Koch, 1840 

3. Galumnella Berlese, 1916 

Type. Galumnella paradoxa Berlese, 1916 



430 Acarology 

4. Galumnopsis Grandjean, 1931 

Type. Galumnopsis holoscripta Grandjean, 1931 

5. Lepidozetes Berlese, 1910 

a. Lepidozetes s. str. 

Type. Lepidozetes singularis Berlese, 1910 

b. Tegoribates Ewing, 1917 (= Lepidoribates Sellnick, 1920) 
Type. Tegoribates subniger Ewing, 1917 

6. Parapelops Jacot, 1938 

Type. Pelops bifurcatus Ewing, 1909 

7. Pelopsisn2A\, 1911 

Type. Pelopsis undiuscula Hall, 1911 

8. PWo/7m/M5 Berlese, 1908 

Type. Pelops phaeonotus Koch, 1844 

9. Propelops J Sicoi, \931 

Type. Propelops pinicus Jacot, 1937 
10. Tectopelops Jacot, 1929 

Type. Pelops laevigatas Nicolet, 1855 

Discussion: Two species, Pelops tardus Koch and P. planicornis 
(Schrank), are known as vectors of the tapeworm Cittotaenia cte- 
noides in Germany. 

The genus Lepidozetes is not typical of this group and may warrant 
subfamily or family rank. It differs mainly in having large, coalesced 
lamellae covering the entire propodosoma. The interlamellar setae are 
small, the hysterosoma overlaps the propodosoma, there are six pairs 
of genital setae, and the chelicerae are normal. 

Galumnidae Grandjean, 1936 

Figures 367 , 368 

Diagnosis: Of the Pterogasterina these mites have large, movable, 
hinged, winglike pteromorphs; the rounded anterior and posterior ends 
project far over the line where they join the body. A suture between 
the propodosoma and the hysterosoma may or may not be present. 
The lamellae are weakly developed or lacking. Each genital plate has 
six setae; the first anterior pair of circumanal setae is on the lateral 
anterior margin of the anal opening. 

Genera and subgenera: 

1. Galumna v. Heyden, 1826 {— Zetes Koch, 1836 = Centroribates 
Berlese, 1914) 



Oribatei 



431 



1804 



1914 



a. Galumna s. str. 
Type. Notaspis alatus Hermann, 

b. Pergalumna Grandjean, 1936 
Type. Oribates nervosus Berlese, 

c. Stictozetes Berlese, 1916 

Type. Oribates {Stictozetes) scaber Berlese, 1916 

d. Vaghia Oudemans, 1917 

Type. Oribates {Stictozetes) stupendus Berlese, 1916 

2. Allogaliimna Grandjean, 1936 
Type. Galumna alamellae Jacot, 1935 

3. Holokalumma J Sicoi, 1929 

Type. Holokalumma coloradensis Jacot, 1929 

4. Pilizetes StWrnck, \9?>1 

Type. Pilizetes africanus Sellnick, 1937 

5. Psamnogalumna Balogh, 1943 

Type. Stictozetes hiingaricus Sellnick, 1925 





Figure 367 Galumna virginiensis 
lacot. Dorsum of female. (After Jacot 
1934) 



Figure 368 Galumna virginiensis 
Jacot. Venter of female. (After Jacot 
1934) 



Discussion: The Galumnidae, or large-winged mites, are rather bi- 
zarre forms which possess large, movable pteromorphs. Several species 
are known to be vectors of tapeworms. Galumna virginiensis Jacot is 
the vector of Moniezia expansa in the United States; G. nervosus 
(Berlese) of Cittotaenia ctenoides in the United States and of Ano- 
plocephala perfoliata in Russia; G. obvius (Berlese) of Moniezia ex- 
pansa, M. benedeni, Anoplocephala perfoliata, and Paranoplocephala 



432 Acarology 

mamillana in Russia and of Cittotaenia ctenoides in Germany; G. 
emarginatum (Banks) and G. nigra (Ewing) of Moniezia expama in 
the United States; Galumna sp. of Moniezia expansa in the United 
States and of Bertiella studeri in Germany. Allogalumna longipluma 
(Beriese) is a vector of Paranoplocephala mamillana in Russia. 

References: 

Jacot, A. P. 1929. American oribatid mites of the subfamily Galumninae. 

Bull. Mus. Compar. Zool. 69(1): 1-37. 
. 1933. The primitive Galumninae (Oribatoidea-Acarina) of the 

Middle West. Amer. Midland Nat. 14(6) :680-703. 
1934. The Galumnas (Oribatoidea-Acarina) of the northeastern 

United States. J. N. Y. Ent. Soc. 42:87-125. 
. 1935. The large-winged mites of Florida. Florida Ent. 19(1): 

1-15; 19(2): 17-31; 19(3):43-47. 

Parakalummidae Grandjean, 1936 

Figures 369, 370 

Diagnosis: Grouped with the Pterogasterina the parakalummids have 
very large, movable, hinged, winglike pteromorphs, which extend an- 
teriorly and posteriorly over the line of attachment to the body. The 





Figure 369 Parakalumma lydia (iacot). Figure 370 Parakalumma lydia (Sacoi). 
Dorsum of female. (After Jacot 1929) Venter of female. (After Jacot 1929) 

propodosoma and hysterosoma are separated by a suture. The lam- 
ellae are weakly developed or lacking. Each genital plate has five setae; 
the anterior pair of circumanal setae lies in front of the anal opening. 



Oribatei 



433 



Genera: 

1. Parakalumma Jacot, 1929 

Type. Neoribates lydia Jacot, 1923 

2. Holozetes Jacot, 1929 

Type. Galumna texana Banks, 1906 

3. Kratzensteinia Oudemans, 1917 
Type. Oribata rugifrons Stoll, 1891 

4. Neoribates Berlese, 1914 

Type. Oribates roubali Berlese, 1900 

5. Neorizetes Jacot, 1933 

Type. Oribata rugosala Ewing, 1909 

6. Protokalumma Jacot, 1929 

Type. Oribata depressa Banks, 1905* 

7. Sandenia Oudemans, 1917 

Type. Galumna georgiae Oudemans, 1914 



Reference: 

Grandjean, F. 1936. Les Oribates de Jean Frederic Hermann et de son 
Pere. Ann. Soc. Ent. de France 105:27-110. 



Epactozetidae Grandjean, 1936 

Figure 371 



Diagnosis: These mites belong 
with the Pterogasterina and have 
large, movable, hinged, winglike 
pteromorphs which extend far 
back and in front of the line of 
joining to the body. The propo- 
dosoma and hysterosoma are sep- 
arated by a suture and there are 
very large lamellae which cover 
the greatest part of the propodo-^ 
soma. Five pairs of setae are pres- 
ent on the genital plates; the 
anterior pair of circumanal setae 
is next to the anterior end of the 
anal opening. 




Figure 371 Epactozetes imitator 
Grandjean. Dorsum of female. (After 
Grandjean 1936) 



434 Acarology 

Genus: 

Epactozetes Grandjean, 1930 

Type. Epactozetes imitator Grandjean, 1930 

Rejerence: 

Grandjean, F. 1936. Les Oribates de Jean Frederic Hermann et de son 
Pere. Ann. Soc. Ent. de France 105:27-110. 

Protoplophoridae Jacot, 1923 

Figure 372 

Diagnosis: These mites are capable of closing up like an armadillo, 
protecting the mouth parts and legs. When the mite is closed, only 
the anal aperture is visible and the genital opening, legs, and gnatho- 
soma are covered by the aspis. The body proper is divided into four 




Figure 372 Aedoplophora glomerata Grandjean. Lateral view of female; lateral 
view of contracted female; detail of tarsus i; anterior view of contracted female. 
(After Grandjean 1932) 

parts: the anterior dorsal or pronotaspis; the dorsal posterior plate or 
metanotaspis or pygidium; and two lateral, symmetrical plates — the 
pleuraspis — which cover a large part of the venter of the hysterosoma. 
The pygidium is movable and can sink entirely into the pronotaspis 
or can be fully withdrawn. Genital plates are immediately behind the 
coxae IV ; the anal plates are directly behind the genital plates and 
between the pleuraspis. 



Oribatei 



435 



Genera: 

1. Protoplophora Berlese, 1910 

Type. Protoplophora palpalis Berlese, 1910 

2. Aedoplophora Grandjean, 1932 

Type. Aedoplophora glornerata Grandjean, 1932 

3. Arthroplophora Berlese, 1910 

Type. Arthroplophora paradoxa Berlese, 1910 

4. Cryptoplophora Grandjean, 1932 

Type. Cryptoplophora abscondita Grandjean, 1932 

5. Prororm/fl Berlese, 1916 

Type. Arthroplophora (Prototritia) armadillo Berlese, 1916 

Discussion: These mites live in humus and rotten roots. There are 
only a few known species, probably owing to the difficulty in collect- 
ing them, as well as insufficient collecting. 

Reference: 

Grandjean, F. 1932. La Famille des Protoplophoridae (Acariens). Bull. 
Soc. Zool. de France 58(1) : 10-36. 

Mesoplophoridae Jacot, 1923 

Figures 373, 374 

Diagnosis: The hysterosoma is not divided into segments. The geni- 
tal opening and anal opening lie in a large ventral plate which is 
connected with the dorsal shield. 





Figure 373 Mesoplophora michaeli- 
ana Berlese. Venter of female. (After 
Berlese 1904) 



Figure 374 Mesoplophora pulchra 
Sellnick. Lateral view of female. 
(After Grandjean 1933) 



436 
Genus: 



Acarology 



Mesoplophora Berlese, 1904 

Type. Mesoplophora michaeliana Berlese, 1904 



Reference: 

Grandjean, F. 1933. Oribates de I'Afrique du Nord. Bull. Soc. d'Hist. Nat. 
de I'Afrique du Nord 24:308-323. 

Phthiracaridae Perty, 1841 

Figures 375-377 

Diagnosis: The hysterosoma is 
not divided by transverse sutures. 
Genital and anal plates lie in a 
large ventral plate which is not 
connected with the dorsal shield. 
Jacot 1930 states: "The out- 
standing character of the Phthira- 
caridae is the ability to withdraw 
the cephalothorax and legs within 
the vault of the notogaster, a de- 
velopment which so much recalls 
the box turtle, armadillo and others. One often reads that the aspis is 
hinged to the abdomen and capable of folding down like the hinged 
lid of a box. This is highly erroneous. There is no hinge. The cephalo- 




Figure 375 Pseudotritia ardiia (Koch). 
Lateral view of female. (After Jacot 
1930) 



Figure 376 Pseudotritia ardua (Koch). 
Genital-anal region. (After Jacot 1930) 




Figure 377 Phthiracarus setosellum 
Jacot. Propodosoma and legs (dotted) 
withdrawn into cavity in upper part of 
hysterosoma and with aspis covering 
the opening. (After Jacot 1930) 



thorax is merely drawn into the upper part of the cavity of the abdomen 
and between the legs, which spread out four on each side. This is done 
in such a way that a chitinous shield or aspis, borne on top of the head 



Oribatei 437 

(with the visor forward) closes the opening hke a Hd on a kettle. The 
ends of the feet (tarsus and claws) fit into the anterior end of this lid, 
i.e., under the visor." 

Key to the Phthiracaridae 

1. Genital and anal plates short and broad; ventral hysterosomal 
plate broadly surrounding anal opening to rear Phthiracarinae 

Genital and anal plates long and narrow; ventral hysterosomal 
plate narrowly surrounding anal opening to rear Euphthiracarinae 

Phthiracarinae Perty, 1841 

Genera and subgenera: 

1. Phthiracanis Perty, 1841 

a. Phthiracarus s. str. 

Type. Acarus piger Scolpoli, 1763 (= Phthiracarus contractilis 
Perty, 1841) 

b. Tropacariis Ewing, 1917 (= Calhoplophora Berlese, 1923) 
Type. Hoplophora carinata Koch, 1841 

c. Trachy hoplophora Berlese, 1923 
Type. Hoplophora magna Nicolet, 1855 

d. Hoplophorella Berlese, 1923 

Type. Hoplophora ciicullatum Ewing, 1909 

2. Steganacarus Ewing, 1917 

Type. Hoplophora anomala Berlese, 1883 

3. Hoplophthiracariis JsLCOt, \933 

Type. Hoploderma histricinum Berlese, 1908 

4. Atropacarus ^Wmg, \9\1 

Type. Hoplophora stricula Koch, 1836 

5. Ginglymacarus Ewing, 1917 

Type. Hoplophora dasypiis Duges, 1834 

6. Hoploderma Michael, 1898 (= Hoplophora Koch, 1836, nom. prae- 

occ.) 
Type. Hoplophora laevigata Koch, 1844 

Euphthiracarinae Jacot, 1930 

Genera and subgenera: 

1. Oribotritia Jacot, 1924 (= Tritia Berlese, 1883, nom. praeocc.) 
Type. Hoplophora decumana Koch, 1836 

2. Indotritia Jacot, 1928 

Type. Tritia krakatauensis Sellnick, 1924 



438 Acarology 

3. Pseudotritia W\\\m2iX\r\, \920 

a. Pseudotritia s. str. 

Type. Tritia monodactyla Willmann, 1919 

b. Phtiracaruhis Berlese, 1920 

Type. Phtiraccirus {Phtiracarulus) perexiguus Berlese, 1920 

4. Euphthiracanis Ewing, 1917 

Type. Phthiracarus fiavus Ewing, 1908 

5. //wmmW/a Oudemans. 1916 

Type. Hiimmelia karpellesi Oudemans, 1916 (= Hoplophora ardua 
Karpelles, 1893) 

6. Peridromotritia Jacot, 1923 

Type. Phthiracarus rotundus Ewing, 1908 

7. Acrotritia Jacot, 1923 

Type. Phthiracarus americanus Ewing, 1 909 

Reference: 

Jacot, A. P. 1930. Oribatid mites of the subfamily Phthiracarinae of the 
northeastern United States. Proc. Boston Soc. Nat. Hist. 36(6) :209- 
261. 



INDEX 



Abacarus, 151 

Abacoptes, 151 

abdomen, 12, 13, 34 

Absoloniana, 228 

absorption, 28 

ACALYPTONOTIDAE, 262, 269, 

Acalyptonotus, 315 

Acamina, 151 

Acanthochela, 82 

acanthoides, 17 

Acaphylla, 151 

Acarapis, 162 

Acarelliptus, 151 

Acaricalus, 151 

acarid, 34 

ACARIDAE, 234, 322, 327, 362 

ACARIDIAE, 14, 30, 320, 387 

ACARINA, 34, 144, 329, 330 

ACARINAE, 330 

Acaroceras, 427 

acarologist, 34 

Acaromantis, 272 

ACARONYCHIDAE, 394 

ACARONYCHINAE, 395 

Acaronychus, 395 

Acarophenax, 164 

Acaropsis, 17, 233 

Acarus, 330 

Acarus, 362 

ACEOSEJIDAE, 53, 58 

Aceosejus, 58 

Acercopsis, 309 

Acercus, 309 

Aceria, 150 

Acheles, 204 

Acherontacarus, 275 

Achipteria, 427 

Achipterina, 427 

Achorolophus, 239 

Achropodophorus, 330 

Acomatacarus, 255 

Acotyledon, 331 

Acronothrus, 404 

Acrotacarus, 353 



Acrotritia, 438 

ACTACARINAE, 271, 273 

Actacarus, 271 

Actineda, 227 

actinochitin, 18 
315 ACTINOCHITINOSI, 18 

Actinoseius, 73 

adanal sucker, 321 

Adoristes, 417 

adult, 33, 34, 52, 253 

Aecosmaris, 242 

Aedoplophora, 435 

Aegyptobia, 221 

aesculifoliae (Oxypleurites), 152 

Africasia, 318 

Agaue, 271 

Agauopsis, 271 

agilis (Anystis), 228 

agricultural 

ACARIDAE, 327 
ANOETIDAE, 358 
CARPOGLYPHIDAE, 340 
ERIOPHYIDAE, 147 
EUPODIDAE, 174 
GLYCYPHAGIDAE, 350 
HEMISARCOPTIDAE, 355 
PHYTOPTIPALPIDAE, 220 
PHYTOSEIIDAE, 87 
PYEMOTIDAE, 164 
TETRANYCHIDAE, 211 

Alabidocarpus, 376 

Albia, 312 

ALBIINAE, 312 

alcohol, 4 

Aleuroglyphus, 330 

alfreddugesi (Trombicula), 257 

algae, 339 

algivorans (Hyadesia), 339 

Alicorhagia, 203 

ALICORHAGIIDAE, 172, 202 

alienus (Carpoglyphus), 341 

Allanalges, 385 

Alliphis, 93 

Alloceraea, 142 

439 



440 



Index 



AUochaetophora, 213 

Allodamaeus, 407 

Allodermanyssus. 84 

Allodispus. 163 

Allogalumna, 431 

Allokrendowskia, 319 

ALLOLAELAPTIDAE, 64 

Allolimnesia, 298 

Alloparasitus, 74 

AUoptes, 384 

Alloribates, 423 

ALLOTHROMBIINAE, 246, 247 

Allothrombium, 247 

Allot hyas, 283 

Allozercon, 56 

Allozetes, 423 

Alycosmesis, 201, 202 

Amansia, 353 

Amasis, 292 

Amazonella, 306 

Amblycentor. 142 

Amblygamasus, 66 

Amblyomma. 142 

AMBLYOMMINAE, 142 

Amblyseius, 88 

Amblysiopsis, 88 

americanus (Pseudocheylus), 226 

americanus (Pygmephorus), 166 

Amerobelba, 409 

AMERONOTHRIDAE. 391, 414 

Ameronothrus. 414 

Ameroseius. 88 

Amerus, 407 

Amnemochthonius, 401 

Amolops, 410 

Amorphacarus, 230 

amphibius (Nanorchestes), 199 

Amphytetranychus, 212, 213 

Anachipteria, 425 

ANACTINOCHITINOSI, 18 

anaerobic, 29 

anal, 9 

anal pedicel, 28 

anal sucker, 35, 321 

Analges. 379 

ANALGESIDAE, 26, 325, 379 

Analgopsis, 379 

Anallopies, 380 

analogy, 1 1 

Anandia, 228 

ananas (Tarsonemus), 169 

Anasicudion, 381 

Anatetranychus, 213 

anatomy, 1 1 

anchora (Myiagles), 369, 370 

Ancystropus, 63 

andersoni (Dermacentor), 144 

Androlaelaps, 94 

anemia. 144, 371 



Atigelia, 404 

angelus (Pterochthonius), 400 

Anisitsiella, 291 

ANISITSIELLIDAE, 262, 265, 291 

ANISITSIELLINAE, 291 

Annectacarus, 399 

annulatus (Boophilus), 144 

Anocentor, 142 

ANOETIDAE, 323, 358 

Anoetoglyphus, 358 

Anoetus, 358 

Anohydrachna, 276, 277 

Anomalothrombium, 248 

anomalus (Caloglyphus), 322 

Anoplocelaeuo, 125 

Anoplocheylus, 226 

Anoplonotus, 381 

anl, 112, 119, 338 

antelope, 75 

antennae, 34 

Antennaepes (Linopodes), 176 

Antennequesoma, 1 1 1 

Antennocelaeno, 125 

Antennocelaeno, 128 

Antennomegistus, 134 

ANTENNOPHORIDAE, 130, 133 

Antennophorus, 133 

Antennoseius, 89 

Antennurella, 133 

Anthocoptes, 151 

antiguensis (Walzia), 228 
Antricola, 138 

anus, 27 
ANYSTIDAE, 173, 226 

ANYSTINAE, 227 
Anystipalpus, 94 
Anystis, 227 

aonidaphagus (Balaustium), 240 
ape, 77 

Aphelacarus, 395 
Apheleuia, 331 
Apionseius, 110 
Aplonobia, 213 
apodeme, 19, 27, 35, 320 
Apolonia, 255 
APOLONIINAE, 254, 255 
Aponomma, 143 
Apostigmaeus, 204 
Apotetranychus, 213 
APTYCTIMA, 387 
ARACHNIDA, 34 
arbusculosa (Bimichaelia), 200 
Archegozetes, 398 
Archeonothrus, 395 
Arctoseius, 94 

arcuatus (Chortoglyphus), 350 
arcuatus (Haemolaelaps), 97 
area sensilligerae, 244 
Argas, 138 



Index 



441 



ARGASIDAE, 137, 138 

Arhodeoporus, 272 

ARRENURIDAE, 262, 269, 317 

Arrenurus, 318 

ARRHENURAE, 261, 262 

Arrhemirella, 318 

Arthrochthonius, 401 

Arthrouothrus, 396 

Arthroplophora, 435 

arthropod, 34, 38, 237 

Asca, 64 

ASCAIDAE, 54, 63 

Ascoschongastia, 256 

aspis, 19 

Astacocroton, 310 

ASTACOCROTONIDAE, 262, 266, 309 

ASTACOPSIPHAGINAE, 273, 274 

Astacopsiphagus, 273 

Astegistes, 417 

Asternolaelaps, 89 

Asternoseius, 89 

asthma, 167, 375 

Astigma, 251 

Atacella, 305 

Atacellides, 305 

Atacoseius, 56 

Atax, 111 

Atax, 305 

Atelopsalis, 272 

A-Thienemannia, 316 

A-THIENEMANNIDAE, 262, 269, 316 

A-THIENEMANNIINAE, 316 

Atomus, 251 

Atopochthonius, 401 

ATOPOMELINAE, 378 

Atopomelus, 377 

ATRACTIDEIDAE, 262, 265, 294 

Atractidella, 302 

ATRACTIDELLIDAE, 301 

Atractides, 295 

Atractidopsis, 302 

Atricholaelaps, 96 

atrium, 29, 30 

Atropacarus, 437 

attenuata (Orthohalarachne), 76 

atticolus (Leptus), 240 

Aturides, 312 

ATURINAE, 312 

Aturus, 312 

auris (Raillietia,) 75 

Austracarus, 255 

Austracus, 150 

australis (Brevipalpus), 222 

australis (Speleognathus), 190 

Austrochirus, 377 

Austrogamasus, 73 

Austrombicula, 255 

Austroteneriffia, 224 

Austrothrombium, 247 



Autenriethia, 227 

Autogneta, 409 

avellanae (Phytoptus), 158 

Avenzoaria, 381 

Avrosia, 169 

AXONOPSAE, 261, 262 

Axonopsalbia, 311 

Axonopsella, 311 

AXONOPSIDAE, 262, 268, 310 

AXON OPSIN AE, 311 

Axonopsis, 311 

baby, 86 

bacillus (Podapolipus), 161 

bacoti (Bdellonyssus), 87 

bags, 6,8 

Balaustium, 239 

balsam, 1 1 

Balzania, 423 

Bandakia, 289 

Banksia, 97, 413 

Banksinus, 423 

Barbaxona, 311 

Barbutia, 204 

Barella, 227 

Bargena, 277 

basifemur, 23, 25 

batatas (Trombicula), 257 

bats, 61, 63, 139, 230, 378 

Bdella, 179, 181 

BDELLIDAE, 24, 171, 178 

bdellids, 30 

BDELLINAE, 179 

Bdellodes, 180 

Bdellonyssus, 85 

Bdellorhynchus, 381 

beak, 19 

Beaurieina, 73 

Bechsteinia, 228 

bedfordi (Entonyssus), 78 

bee, 162, 326 

beetle, 28, 46, 57, 71, 103, 126, 127, 129, 

131 
Beklemishevia, 395 
Belba, 407 

BELBIDAE, 391, 407 
Berlesella, 379 
Berlesia, 91 
Berlesiana, 47 

bicaudatus (Pterolichus), 384 
big-bud mite, 158 
bilobatus (Epidermoptes), 374 
bimaculatus (Tetranychus), 217, 218 
Bimichaelia, 199, 200 
birds, 81, 138, 190, 368, 374, 379, 380, 

381, 382, 383, 384, 385, 386 
biscalatus (Pseudocheylus), 226 
Biscirus, 179 
Blankaartia, 256 



442 



Index 



blastoderm, 33 

blastula, 33 

Blattisocius, 89 

Blomia, 351 

blood, 29 

Bochartia, 239 

body regions, 12 

Bonnetella, 382 

Bonzia, 193, 194 

Boophilus, 143 

Borinqiiolaelaps, 88 

Borrelia, 139 

bovis (Chorioptes), 372 

bovis (Demodex), 237 

bovis (Psoroptes), 372 

Brachychochthonius, 401 

BRACHYCHTHONIIDAE, 400 

Brachychthonius, 401 

Brachylaelaps, 70 

Brachypoda, 311 

Brachypodella, 311 

Brachysternum, 126 

Brachytremella, 103 

Brachytydeus, 191 

brain, 30, 31 

Brevipalpus, 221 

Brevisterna, 85 

brush, 5 

Bruststiele, 329 

Bryobia, 211, 213 

Buchholzia, 382 

buckeye rust mite, 152 

burrows, 57, 139, 363 

butantanensis (Ixodorhynchus), 60 

cadaverum (Glycyphagus), 352 
CAECULIDAE, 173, 210 
Caeculisoma, 239 
Caeculus, 210 
caecum, 28 
Caenobdella, 180 
Caenonychus, 198 
Caenothrombium, 247 
cages, 7, 9 
Calacarus, 151 
Calcarmyobia, 230 
Calepitrimerus, 151 
Caleremaeus, 409 
Calholaspis, 68 
Calhoplophora, 437 
californicus (Tydeus), 192 
Caligonella, 205 
CALIGONELLIDAE, 203 
Caligonus, 205 
Caliphytoptus, 151 
Callidosoma, 239 
Callyntrotus, 151 
Caloglyphus, 330, 333 
Calonyx, 281 



CALOTHROMBIINAE, 246, 248 

Calothrombium, 248 

Calotrachytes, 107 

Calo tydeus, 191 

Calouropoda, 123 

Calurodiscus, 121 

Calvolia, 332 

Calvoppia, 409 

Calyptostoma, 245 

CALYPTOSTOMIDAE, 173. 244 

Calyptozetes, 423 

camerata (Circocylliba), 113 

camerostome, 13, 19, 41 

Camerotrombidium, 248 

Camisia, 403, 404 

CAMISIIDAE, 390, 403 

Campylochirus, 377 

Campylothrombium, 248 

Canestrinia, 353 

Canestriniella, 353 

CANESTRINIIDAE, 321, 323, 353 

canis (Demodex), 236 

Caparinia, 371 

Capeulais, 279 

Capitodiscus, 119 

capitulum, 13, 34 

Capobates, 299 

caprae (Chorioptes), 372 

caprae (Psoroptes), 371 

caprae (Sarcoptes), 365 

capreolus (Cunaxa), 194 

Carabocepheus, 412 

Carabodes, 412 

CARABODIDAE, 391, 412 

Carabodoides, 412 

Caraboecius, 354 

Cardioribates, 421 

Caroloptes, 151 

Carpais, 66 

CARPOGLYPHIDAE, 322, 340 

Carpoglyphus, 340, 341 

caruncle, 25 

Cas, 81 

Caspihalacarus, 272 

castellanii (Tyrophagus), 234, 335 

cati (Notoedres), 365 

cattle, 75, 139, 237 

caulotoon (Myialges), 369 

caustic, 11 

Cavannea, 240 

caves, 57 

caviae (Chirodiscoides), 378 

cavicola (Rhagidia), 183 

Cavilaelaps, 96 

Cecidodectes, 150 

Cecidophyes, 150 

Cederhjelmia, 358, 359 

Celaenogamasus, 45 

CELAENOPSIDAE, 124, 128 



Index 



443 



CELAENOPSINA, 43, 44, 123, 129 

Celaenopsis, 128 

Celaenopsoides, 133 

Celaenosthanus, 133 

cenobilae (Ewingia), 357 

centipedes, 56 

Centrolimnesia, 298 

Centroribates, 430 

Centrotrombidium, 248 

Centrouropoda, 122 

Cephalodiscus, 119 

cephalothorax, !1. 13, 34 

Cephalouropoda, 118 

cepheiformis (Cepheus), 414 

Cepheus, 412 

Cepheus, 413 

Cerachipteria, 427 

Ceratixodes, 31, 142 

Ceratoacarus, 185 

Ceratocelaenopsis, 128 

Ceratoppia, 409 

Ceratothrix, 382 

Ceratozetes, 423 

CERATOZETIDAE, 392, 423 

Cerberothrombium, 250 

CERCOMEGISTIDAE, 130, 132 

Cercomegistus, 132 

Cercothrombium, 251 

Cerocepheus, 413 

Ceroglyphus, 331 

Cerophagus, 351 

Chabrieria, 228 

Chaetodactylus, 351 

Chamobates, 423 

chapini (Hypodectes), 383 

Charassobates, 413 

Chauliacia, 382 

Chaunoproctus, 412 

Chaussieria, 228 

cheese cloth, 8 

Cheiloceras, 381, 382 

Cheiroseius, 88 

chela, 21, 22, 35 

Chelacaropsis, 233 

Cheletogenes. 232, 233 

Cheletoides, 233 

Cheletomimus, 233 

Cheletomorpha, 232, 233 

Cheletophanes, 233 

Cheletophyes, 233 

Cheletopsis, 233 

Cheletosoma, 233 

chelicera, 12, 19, 20, 21, 22, 41, 53 

CHELICERATA, 34 

Chelonotus, 233 

chemo-reception, 15 

chemo-receptor, 17 

Cheylabis, 382 

Cheyletia, 233 



cheyletid, 24 

CHEYLETIDAE, 24, 173, 232 

Cheyletiella, 233, 234 

Cheyletus, 232, 233, 234 

chicken, 81, 86, 258, 374 

chickenpox, 87 

children, 39 

Chirodiscoides, 377 

Chirodiscus, 25, 377 

Chiropteranoetus, 359 

Chiroptonyssus, 85 

chitin, 18 

Chitohydrachna, 277 

chloral hydrate, 10 

chorion, 33 

Chorioptes, 371, 372 

CHORTOGLYPHIDAE, 323, 349 

Chortoglyphus, 350 

Chromotydeiis, 111 

Chyzeria, 250 

■^iliiba, 115 

CILLIBIDAE, 109, 115 

Circocylliba, 113 

CIRCOCYLLIBANIDAE, 109, 113 

circulatory system, 29 

citri (Metatetranychus), 214, 217, 218, 

219 
citrus bud mite, 157 
Claparede organ, 320 
clarki (Eutetranychus), 219 
class, 34 
classification, 34 
Clathrosperchon, 284, 285 
Clathrosperchonella, 284. 285 
CLATHROSPERCHONIDAE, 262, 264. 

284 ■ 
Clausiadinychus, 116 
Claverythraeus, 239 
Cnemidocoptes, 363 
Cocceupodes, 175 
coccinellae (Linobia), 361 
cocciphagus (Saproglyphus), 327 
Coccorchestes, 198 
Coccorhagidia, 183 
Coccotydeus, 192 
cocoons, 228 
Coeloguathus, 330 
Coleoglyphus, 354 
Coleolaelaps, 94 
Coleopterophagus, 354 
coleoptratus (Notaspis), 428 
Coleoscirus, 193 
Coleotydaeus, 192 
collecting. 4 

collegianorum (Coxequesoma), 111 
collembola, 181 
Collohmannia, 396, 397 
Coloboceras, 271 
colon, 27, 28 



444 



Index 



Columellaia, 382 

Comatacarus, 255 

Cometacarus. 351 

Comydinychus, 119 

Conoppia, 409 

Copidognaihopsis, 111 

Copidognathus, 272 

Coprholaspis, 68 

Copriphis. 93 

Coprolaelaps, 70 

Coptophylla, 151 

copulation. 26, 33 

copulatory organ, 21 

coracinus (Liacarus), 417 

cordylensis (Zonurobia), 209 

Corerythrolophus, 239 

Corethrothrombium, 247 

coriaceus (Ornithodoros), 139 

cornea, 32 

Cornubia, 49 

cornutus (Vasates), 157 

Corticacarellus, 300 

Corticacarus, 300 

Cosmiomma. 143 

Cosmiphis, 93 

COSMOCHTHONIIDAE, 400 

Cosmochthonius, 401 

Cosmoglyphus, 331 

Cosmolaelaps, 94 

cotton rat, 87 

coxae, 19, 23, 25, 26, 29, 30, 35, 43 

coxal gland, 28, 29 

Coxequesoma, 110 

COXEQUESOMIDAE, 109, 111 

crab, 357 

Crameria, 382 

crani (Protacarus), 23 

Crassarchus fasciatus, 63 

crassisetosa (Winterschmidtia), 346 

Crastidoglyphus, 351 

Crenohygrobates, 300 

Crenolimnesia, 298 

Creutzeria, 359 

Cricetus frumentarius, 97 

Crinaturus, 312 

Criniscansor, 311 

Crinitodiscus, 119 

crista metopica, 19, 238, 241, 244 

Crotiscus, 256 

Cryptacarus, 399 

CRYPTOGNATHIDAE, 23, 171, 183 

Cryptognathus, 184 

Cryptometasternum, 126 

Cryptoplophora, 435 

Cryptoribatula. 419 

CRYPTOSTIGMATINA, 13 

Ctenerythraeus, 239 

Ctenoglyphus, 351 

Ctenothyas, 286 



CTENOTHYASIDAE, 262, 264, 285 

cucurbita (Cryptognathus), 184 

Cultroribula, 417 

Cultrozetes, 417 

Cunaxa, 193 

CUNAXIDAE, 24, 171, 193, 259, 274 

Cunaxoides, 194 

cuniculi (Chorioptes), 373 

cuniculi (Notoedres), 365 

cuniculi (Psoroptes), 371 

Cupacarus, 151 

curtipilus (Peloribates), 428 

cuticle, 13, 14, 15, 19, 27, 28 

Cyclacarus, 122 

Cyclolaelaps, 96 

Cyclothorax, 45 

Cyclothrix, 278 

Cyllibula, 122 

CYMBAEREMAEIDAE, 391, 406 

Cymbaeremaeus, 407 

Cymoptus, 150 

cynotis (Otodectes), 373 

Cypholaelaps, 95 

Cyrthydrolaelaps, 65 

Cyrtolaelaps, 64 

Cyrtolaelaps, 65 

cysticola (Laminosioptes), 367 

Cyta, 178, 179 

CYTINAE, 179 

Cytodites, 366 

CYTODITIDAE, 324, 366 

Cytoleichiis, 366 

Czenspinskia, 342, 344 

CZENSPINSKIIDAE, 322, 344 

Dactyloscirus, 193 
Dadayella, 318 
Damaeolus, 409 
Damaeus, 407 
Dameobelba, 408 
Damaeolus, 409 
Dameosoma, 410 
Dampfiella, 409 
Dartia, 292 
Dartiella, 292 
Dartonia, 292 

DASYPONYSSIDAE, 98, 99 
Dasyponyssus, 99 
Dekabates, 300 
Demodex, 236 
DEMODICIDAE, 170, 235 
Dendrolaelaps, 64 
Dendrotrombidium, 248 
dentata (Trombicula), 255 
Dentidinychus, 1 16 
Dermacarus, 351 
Dermacentor. 143 
Dermacentorites, 143 
Deraiophorus, 119 



Index 



445 



DERMANYSSIDAE, 55, 83, 86 
DERMANYSSINAE, 86 

DermanyssLis, 21, 84, 86 

Dermation, 373 

Dermatodectes, 371 

Dermatokoptes, 371 

Dermatophagoides, 374, 375 

Dermatophagiis, 371 

DERMOGLYPHIDAE, 325, 380 

Dermoglyphus, 381 

destructor (Glycyphagus), 234, 352 

destructor (Halotydeus), 175, 176 

destructor (Lepidoglyphus), 352 

deutogyne, 152 

deutonymph, 28, 33 

deutovum, 33 

Devonian, 23 

diadema (Bimichaelia), 200 

diander (Podapolipus), 161 

Diapterobates, 423 

DIARTHROPHALLIDAE, 102 

DIARTHROPHALLINA, 43, 44, 102 

Diarthrophallus, 103 

Dicanestrinia, 354 

Diepicrius, 49 

Digamasellus, 71 

digestion, 28 

Digestive system, 27 

Diktyobates, 300 

dimidiatus (Tyrophagus), 335 

Dinocelaeno, 128 

Dinogamasus, 94 

Dinothrombium, 247 

DINYCHIDAE, 117 

Dinychopsis, 119 

Dinychura, 118 

Dinychus, 116 

Diphaulocylliba, 120 

Diphtheroglyphus, 332 

DIPLODONTINAE, 283 

Diplodontus. 283 

Diplogyniella, 126 

DIPLOGYNIIDAE, 124, 127, 129 

DIPLOGYNIINAE, 125 

Diplogyniopsis, 126 

Diplogynium, 125 

Diplohydrachua, 277 

Diplokoenikea, 306 

Diplopodophilus, 130 

Diplostaspis, 63 

Diplothrombium, 248 

Dipolyaspis. 107 

Diptilomiopus, 151 

Discomegistus, 56 

Discopoma, 115, 119 

Discotrachytes, 116 

Discourella, 110, 111 

DISCOURELLIDAE, 108, 109, 110 

Discozercon, 56 



DISCOZERCONIDAE, 53, 55 

Dispaiipes, 162 

Dispersipiona, 308 

Dissorhiiia, 410 

Distolebertia, 293 

Dithinozercon, 99 

Diurodinychus, 117 

Divarinychus, 214 

Diversipes, 163 

diverticulum, 27 

Djeboa, 314 

Djeboella, 315 

DJEBOINAE, 314 

docta (Acaropsis), 17 

Dodecabates, 300 

dog, 77, 236 

Dolaea, 94 

Dolicheremaeus, 409 

Dolichotetranychus, 149, 221, 222 

Doloisia, 256 

domesticus (Glycyphagus), 352 

Donia, 73 

Donndorfia, 344 

dorcicola (Canestrinia), 354 

drag, 6 

Dromeothrombium, 248 

Drymobates, 421 

Drymobatoides, 421 

duck, 39 

Dugesia, 242 

Duralimnesia, 298 

Dwiguhskyia, 47 

dye, 15 

Eadiea, 230 

ear, 9, 371, 372 

Eberhardia, 331 

Ebertia, 330 

ecdysis, 29 

echidninus (Echinolaelaps), 97 

Echinolaelaps, 96 

Echinomegistus, 134 

Echinonyssus, 85 

echinopus (Rhizoglyphus), 333. 334 

Echinoseius, 89 

Echinothrombium, 249 

Ecpolopsis, 306 

Ecpolus, 306 

ectostracum, 14 

Edwardzetes, 423 

egg, 33 

EigentUche Haare, 16 

ejaculatory duct, 33 

Elaphrolaelaps, 70 

Ellsworthia, 85 

elongatus (Dermoglyphus), 384 

elytra, 8 

emarginatum (Galumna), 432 

Embolacarus, 405 



446 



Index 



embryo. 33 

empodium. 25 

ENCENTRIDOPHORINAE, 306 

Encentridophorus, 306 

Encylliba, 122 

ENDEOSTIGMATA, 172, 196 

Endopalpiger, 142 

endoskeleton, 26 

Endotrombiciila, 256 

Enemothrombium, 249 

Eniochthonius, 401 

ensifera (Radfordia), 231 

Ensliniella. 343. 344 

ENSLINIELLIDAE. 321, 322. 343 

ENTEROHALACARINAE. 273, 274 

Enterohalacarus. 273 

entomophagus (Thyreophagus), 334 

ENTONYSSIDAE, 55, 78 

ENTONYSSINAE, 78, 79 

Entonyssus, 79 

enzyme, 28 

Eobrachychthonius, 401 

Eohypochthonius. 401 

Eotetranychus. 212, 213 

Eothrombium. 250 

Epactozetes. 434 

EPACTOZETIDAE. 392, 433 

EPICRIIDAE. 47, 48 

Epicriopsis. 73 

Epicrius, 49 

Epicroseius, 47 

Epidermoptes. 373 

EPIDERMOPTIDAE. 324, 373 

Epieremulus, 410 

Epilohmannia, 398 

EPILOHMANNIIDAE, 390, 398 

Epilohmannoides, 402 

epimeron, 27 

epiostracum, 14 

Epiphis, 73 

Episeiella, 89 

Episeiiis, 89 

Epistomalycus, 203 

epistome, 19, 41 

Epitetranychus, 213 

Epitrimerus, 151 

Eporibatula, 421 

equi (Chorioptes), 372 

equi (Demodex), 237 

EREMAEIDAE, 391, 408 

Eremaeozetes. 413 

Eremaeus. 409 

Eremella. 407 

Eremobelba, 410 

Eremobodes, 413 

Eremulus. 410 

Ereynetes. 186, 187 

EREYNETIDAE, 171, 186 

Eriophyes, 150 



ERIOPHYIDAE, 146, 147, 221 

eriophyids, 214 

ERIOPHYINAE, 149, 150 

eriophyoides (Tenuipalpus), 148, 221 

eruditus (Cheyletus), 234 

ERYTHRACARINAE, 227, 228 

Erythracarus, 228 

ERYTHRAEIDAE, 173, 237 

Erythraeus, 239 

Eryihrellus, 339 

Erythrocheylus. 228 

Erythroides, 239 

Erythrolophus, 239 

Erythrombium, 239 

Eschatocephalus, 142 

esophagus. 27, 28, 30 

essigi (Aceria), 158 

Ettmulleria. 251 

Eubrachylaelaps. 96 

Eucanestrinia, 354 

Eucanis, 37 

Eiicheyla, 233 

Eucheyletia, 233 

Euepicrius, 68 

Eufedrizzla, 133 

Eugamasus, 66 

Eugynolaelaps, 95 

Euhaemogamasus. 83 

Euholocelaeno, 68 

Eulabidocarpus, 377 

Eulaelaps. 96 

Eulohmannia. 396 

EULOHMANNIIDAE, 390, 396 

Eunicolana, 186 

Eupalopsellus, 205 

Eupalopsis. 205 

Eupalus, 194 

Eupatra, 283 

Eupatrella, 317 

EUPATRELLIDAE, 317 

Eupelops. 429. 430 

EUPHTHIRACARINAE, 437 

Euphthiracarus, 438 

Euplatylophus, 239 

Eupodes. 26. 175 

EUPODIDAE, 172, 174 

Eupodolophus, 240 

Eupterotegaeus, 413 

Eurychiroides. 377 

Euryparasitus, 71 

Eitryparazetes, 428 

Eurytetranychus, 213 

Euryzoniis, 7)11 

Euschongastia, 256 

Eustathia, 382 

Eustigmaeus, 205 

Eutalpacarus, 230 

Eutarsopolipus, 160 

Eutegaeus. 413 



Index 



447 



Eutetranychus, 213 

Euthyas, 284 

EUTHYASINAE, 284 

Eutogenes, 233 

Eutrachytes, 115 

EUTRACHYTIDAE, 109, 115 

Eutrichothrombium, 249 

Eutrombicula, 256 

EUTROMBIDIINAE, 247, 248 

Eutrombidium, 248 

Euzercon, 127 

EUZERCONIDAE, 124, 127, 129 

Euzetes, 424 

Eviphis, 93 

Ewingana, 230 

Ewiugella, 233 

Ewingia, 357 

EWINGIDAE, 323, 357 

excretory tubule, 28, 29 

Exopalpiger, 142 

Exoribatula, 421 

eye, 9, 30, 32 

EYLAIDAE, 23, 262, 263, 279 

EYLAINAE, 279 

Eylais, 279 

Falculifer, 382 
FALCULIFERIDAE, 380 

Fallopia, 238, 239 

famulus, 17 

Favettea, 385 

feces, 9, 28 

Fedrizzia, 43, 135 

FEDRIZZIIDAE, 130, 135 

FEDRIZZIINA, 43, 44, 129, 130 

Feltria, 304 

Feltriella, 304 

FELTRIIDAE, 262, 263, 303 

female, 21, 33 

femur, 25, 26 

Ferminia, 340, 341 

feroniarum (Histiostoma), 359 

fertilization, 33 

Fessonia, 242 

Fessoniella, 240 

FESSONIINAE, 243 

ficus (Aceria), 153 

fievre boutonneuse, 144 

fig mite, 153 

filariasis, 87 

fixed digit, 21, 23 

flannel, 5, 6 

Flavionyssus, 81 

Flexipalpus, 152 

floridanus (Megisthanus), 45, 46 

fockeui (Vasates), 158 

Foliomyobia, 230 

Foliotrombidium, 249 

folliculorum (Demodex), 236 



Fonsecaonyssus, 85 
Fonsecia, 256 
food 

ACARIDAE, 327 

CARPOGLYPHIDAE, 340 

GLYCYPHAGIDAE, 350 
Forcellinia, 338 
FORCELLINIIDAE, 322, 337 
forceps, 5 
fore-gut, 27 
Forelia, 308 
FORELIINAE, 308 
Formica, 163 

fragilis (Alicorhagia), 203 
Freyana, 382 
Frischia, 423 
Frontipoda, 294 
FRONTIPODOPSINAE, 313 
Frontipodopsis, 313 
Froriepia, 331 
Froweinia, 361 
fungus, 375 
funnel, 6, 7 
Fusacarus, 349, 350 
fusca (Hyadesia), 340 
Fuscozetes, 427 
Fuscuropoda, 122 
Fusohericia, 352 

Gabucina, 382 

Gahrliepia, 255 

gallinae (Dermanyssus), 86 

gallinae (Knemidokoptes), 365 

Gallus gallus, 326 

Galumna, 430 

Galumnella, 429, 430 

GALUMNIDAE, 393, 430 

Galumnopsis, 429, 430 

Gamasellus, 64 

Gamasholaspis, 68 

GAMASIDES, 41, 43, 44, 52, 53, 99, 104, 

105 
Gamasiphis, 73 
Gamasodes, 72 
Gamasolaelaps, 71 

GAMASOLAELAPTIDAE, 54, 71, 74 
Gamasiis, 66 
Gammaphytoptus, 151 
ganglion, 30 
Garsaultia, 331 
Gateria, 255 
Geayella, 319 
Geayia, 319 
Geayidea, 319 
Geckobia, 208 
Geckobiella, 208 
geese, 39 
Geholaspis, 68 
Gehypochthonius, 395 



448 



Index 



Geneiadolaelaps, 85 

genital, 9, 30 

genital opening, 43 

genital sucker, 33 

genu, 17. 23, 25 

Georgella, 283 

Georgia, 249 

Giardius, 361 

Giebelia, 383 

Gigantolaelaps, 96 

gill books, 34 

Ginglymacarus, 437 

gland, 15, 16 

Globozetes, 424 

glycerin. 10 

GLYCYPHAGIDAE, 323, 350 

Glycyphagus, 351 

Glyphanoetus, 359 

Gnaphiscus, 294 

Gnaphoxus, 294 

gnathosoma, 12, 13, 19 

Gohiera. 352 

Gradidorsum. 410 

grain itch. 166 

graminum (Siteroptes), 166 

granati (Tenuipalpus), 222 

Grandiella. 354 

Grandjeanacarus. 395 

grape rust mite, 157 

grassi (Podapolipus), 161 

Greeuia, 94 

Greeniella, 91 

Greeniella, 94 

grocers' itch, 352 

guanin, 29 

guentheri (Zwickia), 359 

gum arabic, 10 

gun, 8 

Guntherana, 256 

Gustavia, 419 

GUSTAVIIDAE, 391, 418 

Gymnobates, 419 

Gymnodamaeus, 408 

Gymnodampia, 410 

Gymnolaelaps, 94 

Gymnonothrus, 404 

habitat, 1 
habits, 39 
Haemalastor, 142 
Haemaphysalis, 143 
HAEMOGAMASIDAE, 55, 82, 83 
Haemogamasus, 82 
Haemolaelaps, 96 
Hafenrefferia, 420 
hagensis (Calvolia), 336 
HALACARIDAE, 259, 262, 269 
HALACARINAE, 271, 274 
Halacarus. 271 



Halarachne, 77 
HALARACHNIDAE, 55, 76 
Haleiipalus, 194 
Halixodes, 273 
HALIXODINAE, 273, 274 
Halleria, 382 

Haller's organ, 31, 32, 34, 35, 42 
Halolaelaps, 71 
Halotydeus, 175 
Halouropoda, 120 
Halozetes, 410 

hamadryas (Winterschmidtia), 346 
Hammeria, 424 
Hammertonia, 79 
Hamohalacarus, 273 
Hannemania, 255 
Haplochthonius, 402 
Haplozetes, 428 
HAPLOZETIDAE, 392, 428 
Haptosoma, 311 
HARPAGOPALPINAE, 316 
Harpagopalpus, 316 
Harpicephalus, 230 
Harpirhynchus, 229, 230 
Hartingia, 380 
Hauptmannia, 239 
hay itch, 166 
heart, 29 
Heaslipia, 256 
Helix pomata, 187 
Hemialges, 379 
Hemibrachypoda, 311 
Hemilaelaps, 85, 96 
Hemileius, 421 
Heminothrus, 404 
Hemisarcoptes, 355 
HEMISARCOPTIDAE, 324, 355 
Hemitarsonemus, 169 
Hemitromhicula, 278 
Hepatozoan criceti, 97 
Hepatozoan muris, 97 
Hericia, 352 
Hermannia, 404 
Hermanniella, 416 
HERMANNIELLIDAE, 390, 415 
HERMANNIIDAE, 390, 404 
hermsi (Ornithodoros), 139 
HETEROCHEYLINAE, 225 
Heterccheylus, 225, 226 
Heterochthonius, 402 
heterocomus (Czenspinskia), 345 
HETERODIPLOGYNIINAE, 125 
Heterodiplogynium, 126 
Heterodispus, 163 
Heterolaelaps, 96 
heteromorphic, 169 
HETEROPSORIDAE, 324, 368 
Heteropsorus, 368 
Heteropus, 164 



Index 



449 



Heteroteneriffia, 224 

Heterotrombidium, 251 

Heterozercon, 56 

HETEROZERCONIDAE, 56 

Hevea, 342 

Hexalebertia, 293 

Hexatax, 305 

Hexathrombium, 251 

Hexaxonopsis, 311 

hind-gut, 28 

Hiotrombidium, 249 

H:rstesia. 85 

Hirstiella, 208 

Hirstiosoma, 242 

HIRSTIOSOMINAE, 243 

Hirstithrombium, 248 

Hirstonyssus, 85 

Hispidosperchon, 291 

Histiogaster, 327, 331 

Histiostoma, 334, 359 

History, 3 

Hjartdalia, 312 

Holaspulus, 68 

HOLCOTROMBIDIINAE, 247, 250 

Holcotrombidium, 250 

Holocelaeno, 68 

Holokalumma, 431 

Holoparasitus, 66 

Holostaspella, 68 

Holostaspis, 94 

HOLOTHYRIDAE, 38 

HOLOTHYROIDEA, 14, 18, 20, 21, 29, 

36, 38 
Holothyrus, 39 
Holozetes, 433 
Homocaligus, 205 
homology, 11 
honey bee, 163 
hopkinsi (Raillietia), 75 
Hoploderma, 437 
Hoplolaelaps, 74 
HoplomegistLis, 45 
Hoplomolgus, 180 
Hoplophora, 437 
Hoplophorella, 437 
Hoplophthiracarus, 437 
Hoploscirus, 180 
Hoploseius, 89 
Hoplothrombium, 251 
horridus (Euhaemogamasus), 15 
horse, 72 
Horstia, 344 
host, 8, 9 
hot springs, 287 
housefly, 69 
household 

ACARIDAE, 327 

ARGASIDAE, 139 



household (continued) 

DERMANYSSIDAE, 83 

EPIDERMOPTIDAE, 373 

GLYCYPHAGIDAE, 350 

IXODIDAE, 141 

TETRANYCHIDAE, 211 
Hoyer's, 10 
Huitfeldtia, 306 
HUITFELDTIINAE, 306 
Humerobates, 424 
Hummelia, 438 
Hungarohydracarus, 316 
Hyadesia, 339 
HYADESIDAE, 322, 339 
Hyalomma, 143 
Hyalommasta, 143 
Hyalommina, 143 
Hybalicus, 196 
HYDRACARINA, 259 
hydracarinid, 32 
Hydrachna, 277 
HYDRACHNAE, 261, 262 
HYDRACHNELLAE, 170, 259 
HYDRACHNIDAE, 262, 263, 276 
Hydrobaumia, 291 
Hydrochoreutes, 309 
Hydrodroma, 282 

HYDRODROMIDAE, 262, 264, 281 
Hydrogamasus, 73 
Hydrovolzia, 275 
HYDROVOLZIAE, 260, 262 
Hydrovolziella, 275 

HYDROVOLZIIDAE, 259, 262, 263. 274 
Hydrozetes, 389, 410 
HYDRYPHANTAE, 261, 262 
Hydryphantes, 282 

HYDRYPHANTIDAE, 262, 264, 282 
HYDRYPHANTINAE, 282 
Hygrobatella, 300 
Hygrobates, 299 

HYGROBATIDAE, 262, 267, 299 
Hygrobatides, 300 
HYGROBATINAE, 299 
Hygrobatomegapus, 301 
Hygrobatopsis, 300 
Hygroribates, 413 
Hyletastea, 93 
HYLETASTINAE, 93 
Hyperalges, 379 
HYPOASPIDINAE, 93 
Hypoaspis, 93 
Hypochthoniella, 401 
HYPOCHTHONIIDAE, 390, 400 
Hypochthonius, 401 
Hypodectes, 383 
hypodermis, 13, 15 
hypopi, 333 
hypostome, 20, 21, 34, 35, 41 



450 



Index 



hypostracum, 14 
Hyracarus, 255 
hysterosoma, 12, 13, 19 
Hystrichonychus, 213 

Ich^ronyssus, 85 

idiosoma, 12, 13, 18, 19, 27 

Imparatoppia, 410 

Imparipes. 163 

incisellus (Trichoribates), 425 

Indocentor, 143 

Indoribates, 425 

Indotritia, 437 

inermis (Cunaxa), 194 

Ingrassia, 379 

inornatus (Brevipalpus), 221, 222 

insects, 18, 67, 71, 91, 123, 126, 134, 135, 

136, 159, 163, 164, 243, 344, 346, 

360, 362, 370 
integument, 13, 14, 15, 18, 27, 31, 32 
intestine, 28, 29 
iodine, 18 
Iphidinychus, 47 
Iphidosoma, 94 
Iphidozercon, 93 
Iphidulus, 88 
IPHIOPSIDAE, 55, 90 
Iphiopsis, 91 
Iphis, 91 
Iphis, 93 
Iphiseius, 89 
Ischnolaelaps, 96 
Ischyrognathus, 272 
Ischyropoda, 83 
Isobactrus, 271 
Isoglyphus, 331 

isometri (Pimeliaphilus), 207, 208 
lugoribates, 424 
Ixobioides, 60 
Ixodes, 142 

IXODIDAE, 137, 140, 141 
Ixodiderma, 208 

IXODIDES. 15, 27, 30, 34, 40, 137 
IXODINAE, 142 
IXODORHYNCHIDAE, 53, 60 
Ixodorhynchus, 60 

Jacobsonia, 91 

Jacotella, 408 

Janetiella, 118 

jar, 7, 8 

Javathyas, 283 

Joelia, 426 

Johnstoniana, 248 

JOHNSTONIANINAE, 246, 247, 248 

Jordensia, 94 

Joiibertia, 385 

Jugatala, 424 

julidicolus (Caloglyphus), 335 



Julolaelaps, 94 
Jurabates, 419 
jute, 342 

Kalobrachypoda, 311 
Kashmirothyas, 283 
Kawamuracarus, 292 
Kenya typhus, 145 
kerguelenensis (Hyadesia), 340 
Klinckowstroemia, 135 
Knemidokoptes, 363 
Kobus defassa ugandae, 75 
Koenikea, 306 
Koenikella, 306 
Kolenationyssus, 85 
Komiia, 315 
Kongsbergia, 304 
Kramerella, 382 
Kratzensteinia, 433 
Krendowskia, 318 
Krendowskiella, 318 
KRENDOWSKIIDAE, 262, 269, 31? 
Kyphohygrobatella, 300 
Kyphohygrobates, 300 

label, 11 

LABIDOCARPINAE, 378 

Labidocarpus, 377 

Labidophorus, 352 

Labidostomma, 185 

LABIDOSTOMMIDAE, 172, 184 

labrum, 20, 36 

lacinae, 18 

lactic acid, 10, 11 

lactophenol, 11 

Laelantennus, 94 

Laelaps, 95 

LAELAPTIDAE, 55, 91, 93, 95 

LAELAPTINAE, 93 

Laelaspis, 94 

Laelaspulus, 95 

Laelogamasus, 64 

laevigatus (Scheloribates), 389, 422 

laevis (Knemidokoptes), 365 

lagena (Cryptognathus), 184 

Lagenoglyphus, 331 

Lamellaxona, 312 

laminipes (Fusacarus), 350 

Laminosioptes, 367 

LAMINOSIOPTIDAE, 324, 367 

Laminothrombium, 249 

lapidarius (Biscirus), 180, 181 

LARDOGLYPHIDAE, 323, 347 

Lardoglyphus. 347 

Larinyssus, 81 

larva, 33, 34, 43, 51, 254 

Lasioseius, 88 

Lasiotydeus, 191 

Lasius, 163 



Index 



451 



laticeps (Tarsonemus), 169 

latipes (Scheloribates), 422 

latus (Hemitarsonemus), 169 

Lawrencoppia, 410 

Lebertia, 293 

LEBERTIAE, 261, 262 

LEBERTIIDAE, 262, 265, 293 

LEBERTIINAE, 293 

Ledermulleria, 205 

Leeuwenhoekia, 255 

LEEUWENHOEKIINAE, 254, 255 

leg, 24, 25, 30, 31, 33, 34, 41 

Leiodinychus, 121 

Leiognathus, 85 

Leioseius, 88 

Leiosoma, All 

Leiostaspis, 63 

Lemienia, 306 

Lentungula, 339 

Lenzia, 342 

Leonardiella, 119 

Lepidixodes, 142 

Lepidoglyphus, 352 

Lepidorihates, 430 

Lepidozetes, 430 

Lepronyssoides, 85 

Lepronyssus, 85 

Leptalicus, 198 

Leptantennus, 133 

Leptogamasus, 74 

Leptolaelaps, 94 

Leptopterotrichophorus, 307 

Leptothrombium, 248 

Leptotrombidium, 256 

Leptus, 239, 240 

Lesseria, 398 

Lethaxona, 311 

leucocytes, 29 

lewisi (Brevipalpus), 222 

lewisi (Tetranychus), 219 

LIACARIDAE, 391, 417 

Liacarus, 417 

Licneremaeus, 410 

Licnobelba, 410 

Licnodamaeus, 410 

Licnoliodes, 410 

Liebstadia, 421 

life cycle, 33, 38, 39, 77, 79, 83, 144, 252, 

257 
light, 7 

Ligilaelaps, 97 

limacum (Riccardoella), 187, 190 
Limnesia, 298 
Limnesicula, 298 
Limnesides, 298 
Limnesiella, 298 
Limnesiellula, 298 
LIMNESIIDAE, 262, 266, 297 
LIMNESIINAE, 298 



Limnesiopsides, 298 

Limnesiopsis, 298 

LIMNOCHARAE, 261, 262 

Limnochares, 278 

LIMNOCHARIDAE, 23, 262, 263, 277 

LIMNOHALACARINAE, 273, 274, 278 

Limnohalacarus, 273 

Limnolegeria, 293 

Limnozetes, 424 

Linobia, 360 

LINOBIIDAE, 323, 360 

Linocoptes, 360 

Linopodes, 175 

Linotetranus, 213 

lintneri (Tyrophagus), 334 

Liodes, 405 

Liostigmaeus, 205 

Liroaspis, 47 

LIPONISSIDAE, 86 

LIPONISSINAE, 86 

Liponissus, 123 

Liponysella, 85 

Liponyssoides, 85 

Liponyssus, 85 

LIROASPIDAE, 47 

LIROASPINA, 43, 44, 46 

Liroapis, 47 

LISTROPHORIDAE, 324, 376 

LISTROPHORINAE, 378 

Listrophoroides, 377 

Listrophoroides, 111 

Listrophorus, 376 

Litarachna, 295 

Litomosoides carinii, 87 

litter, 2 

littoralis (Pontoppidania), 336 

lizard, 208 

Ljania, 311 

Ljunghia, 94 

Lobocephalus, 64 

Lobogynioides, 126 

Lobogynium, 126 

Locusta migratoria, 161 

Locustacarus, 160 

Loeflfler's syndrome, 375 

Lohmannella, 272 

LOHMANNELLINAE, 272, 273 

Lohmannia, 399 

LOHMANNIIDAE, 390, 399 

Lohohalacarus, 272 

longipluma (Allogalumna), 432 

longilinealis (Hirstiosoma), 243 

Longolaelaps, 96 

LORDALYCHIDAE, 172, 195 

Lordalycus, 196 

lordi (Czenspinskia), 345 

Lorryia, 192 

Lucasiella, 239 



452 



Index 



lucerne flea, 180 
Lucoppia, 410 
Lundbladia, 283 

Mackiella, 150 

MACKIELLINAE, 150 

Macrocheles. 67 

MACROCHELIDAE, 26, 54, 67 

Macrodinychus, 121 

Macrolaelaps, 96 

Macrolaspis, 69 

MACRONYSSIDAE, 86 

Macronyssus, 85 

Macrostigmaeus, 205 

maculata (Diphtheroglyphus), 336 

major (Penthaleus), 176 

Malacoangelia, 402 

MALACONOTHRIDAE, 390, 403 

Malaconothrus, 403 

males, 21, 26, 30, 33, 43, 51, 53 

mali (Lorryia), 192 

malus (Hemisarcoptes), 355, 356 

Mamersa, 283 

Mamersella, 292 

Mamersellides, 292 

Mamersides, 292 

MAMERSINAE, 283 

MAMERSOPSIDAE, 262, 265, 288 

Mamersopides, 292 

Mamersopsis, 288 

mandible, 34 

Mania, 293 

Manisicola, 85 

Manitherionyssus, 85 

Manotonia, 293 

Manriqiiia, 248 

Mantidoglyphus, 344 

Margaropus, 143 

Marginura, 122 

marina (Heteroteneriffia), 224 

marinus (Ameronothrus), 414 

Marquesania, 377 

Masthermannia, 405 

Mauduytia, 359 

Mealia, 374 

MEALIIDAE, 373 

medical 

ACARIDAE, 327 
ARGASIDAE. 137 
DERMANYSSIDAE, 83 
DEMODICIDAE, 235 
EPIDERMOPTIDAE, 373 
GLYCYPHAGIDAE, 350 
HAEMOGAMASIDAE, 82 
HOLOTHYRIDAE. 38 
IXODIDAE, 141 
LAELAPTIDAE, 92 
PYEMOTIDAE, 164 
SARCOPTIDAE, 362 



medical (continued) 

TARSONEMIDAE, 168 
TROMBICULIDAE, 253 
TYDEIDAE, 190 

Mediolata, 205 

Megabates, 300 

Megacanestrinia, 354 

Megachaetochela, 126 

Megaliphis, 73 

Megalolaelaps, 70 

Megaluracarus, 318 

Megapella, 301 

Megapoides, 301 

Megapus, 301 

MEGAPUSINAE, 301 

Megatromhicula, 256 

Megistanus, 45 

MEGISTHANIDAE, 45 

MEGISTHANINA, 43, 44, 45, 46 

Megisthanus, 45, 46 

Megninia, 379 

megnini (Otobius), 139 

Megninietta, 331 

megninii (Coleopterophagus), 354 

Meinertula, 126 

MEINERTULINAE, 125 

Melanotydeus, 191 

Melanozetes, 424 

Melichares, 89 

Meliponaspis, 94 

Melisia, 352 

Melittiphis, 93 

Meristacarus, 399 

Meristaspis, 63 

Mesalges, 379 

Mesobatella, 301 

Mesobates, 301 

Mesofeltria, 304 

Mesolaelaps, 96 

Mesoplophora, 436 

MESOPLOPHORIDAE, 18, 393, 435 

MESOSTIGMATA, 14, 15, 18, 34, 40, 44 

Mesothrombium, 247 

Messoracarus, 133 

metabolism, 29 

Metadinychus, 116 

Metagynella, 122 

metamere, 12 

metamerism, 11 

metamorphosis, 34 

Metanalges, 379 

Metaparositus, 71 

metapodosoma, 12, 13 

Metarhombognathus, 271 

Metatetranychus, 213 

Meteylais, 279 

methocellulose, 10 

Metrioppia, 410 

Michaelia, 200, 382, 399 



Index 



453 



Michaelichus, 382 

Michaeliella, 118 

Micreremus, 407 

Micrereunetes, 187 

Micriphis, 73 

Microchelys, 382 

Miciodiplogynium, 126 

Microdispodides, 163 

Microdispus, 163 

MICROGYNIIDAE, 50 

MICROGYNIINA, 43, 44, 46, 50 

Microgynium, 51 

Microlichus, 374 

Micromegistus, 134 

MICROSEJIDAE, 50, 51 

Microsejus, 52 

microsensory seta, 17 

Microsmaris, 239 

Microspalax, 382 

Microtegeus, 412 

MICROTROMBIDIINAE. 247, 248 

Microtrombidium, 248 

Microtydeus, 191 

Microzetes, 427 

MICROZETIDAE, 392, 426 

Micruracaropsis, 318 

Micruracarus, 318 

Midea, 313 

MIDEIDAE, 262, 269, 313 

MIDEOPSAE, 261, 262 

Mideopsella, 315 

MIDEOPSELLINAE, 315 

MIDEOPSIDAE, 262, 269, 314 

MIDEOPSINAE, 314 

Mideopsis, 314 

mid-gut. 27, 28 

millipedes, 56 

minor (Dermoglyphus), 384 

Minunthozetes, 424 

minuta (Oribatula), 422 

minutus (Nanacarus), 362 

minutus (Scutovertex), 413 

Miraxona, 311 

Miraxonella, 311 

Miraxonides, 312 

Mixobates, 301 

Mixolebertia, 293 

Mixosperchon, 291 

Mochlozetes, 424 

molds, 153 

mole, 350 

molestus (Tydeus), 192 

Molgus, 180 

Momonia, 315 

Momoniella, 315 

MOMONIINAE, 315 

Monalichus, 198, 202 

Monatractides, 295 

Monaulax, 150 



Monieziella, 331 
Monobates, 300 
Monoceronychus, 213 
Monochetus, 150 
Monohydrachna, 277 
MonojoLibertia, 385 
Monokoenikea, 307 
Monotrichobdella, 178, 179 
Monotromhidiiim, 239 
Montesauria, 385 
Monunguis, 251 
motatorius (Linopodes), 176 
moubata (Ornithodoros), 139 
mounting, 10 
mouth, 19, 20 
movable digit, 21, 22 
Mucronothrus, 403 
Mulriiis, 407 
Mundamella, 316 
MUNDAMELLINAE, 316 
Mungosicola, 97 
muris (Notoedres), 365 
Musca domestica, 166 
muscae (Macrocheles), 69 
muscardini (Demodex), 236 
muscle, 27 

musculi (Myobia), 230 
musculinus (Myocoptes), 378 
mutans (Knemidokoptes), 365 
Mycetoglyphus, 331 
Mycobates, 424 
Myialges, 369 

MYIALGESIDAE, 324, 369 
Myialgopsis, 369 
Myianoetus, 359 
Myobia, 230, 378 
MYOBIIDAE, 171, 229 
Myocoptes, 377 
myocoptic mange, 378 
MYOCOPTINAE, 378 
Myonyssoides, 85 
Myonyssus, 85 
Myotrombicula, 256 
myriopods, 91, 131, 134, 135, 136 
Myrmeciphis, 94 
myrmecophil, 112, 113 
Myrmicotrombium, 248 
Myrmoglyphus, 331 
Myrmolaelaps, 94 
Myrmoleichus, 94 
Myrmonyssus, 95 
Myrmozercon, 95 
Mysolaelaps, 96 

Najadicola, 306 
NAJADICOLINAE, 306 

Nalepella, 150 

namaquensis (Ptilophus), 241 

NANACARIDAE, 323, 361 



454 



Index 



Nanacarus, 361 

Nanhermannia, 397 

NANHERMANNIIDAE, 390, 397 

Nanorchestes, 198 

NANORCHESTIDAE, 172, 197 

nasicolus (Labidocarpus), 378 

Nasozetes, 410 

natalensis (Neocheylus), 226 

Nautarachna, 303 

NAUTARACHNIDAE, 262, 267, 303 

Nealges, 379 

Neamerus, 407 

neglectus (Saproglyphus), 327 

neivai (Dasyponyssus), 99 

Nellacarus, 427 

Nemnichia, 67 

Neoalbia, 312 

Neoaxona, 312 

Neoaxonopsella, 311 

Neoaxonopsis, 312 

Neoberlesia, 95 

Neobrachypoda, 312 

Neocalonyx, 281 

NEOCARIDAE, 36 

Neocarus, 37 

Neocelaeno, 128 

Neocepheus, 413 

Neocheyletiella, 233 

Neocheylus, 225, 226 

Neocypholaelaps, 95 

NEODIPLOGYNIINAE, 125 

Neodiplogynium, 126 

Neodiscopoma, 119 

Neoeucheyla, 233 

Neogymnobates, 428 

Neohygrobates, 300 

Neoiochoronyssus, 85 

Neokoenikea, 307 

Neokrendowskia, 318 

Neolabidocarpus, 377 

Neolaelaps, 96 

Neolehertia, 293 

Neolimnesia. 298 

Neolimnochares, 278 

Neoliodes. 405 

NEOLIODIDAE, 390, 405 

Neoliponyssus, 85 

Neomegistus, 134 

Neomolgus, 180 

Neomyobia, 230 

Neonyssoides, 81 

Neonyssus, 81 

Neo-Oudemansia, 132 

Neoparalaelaps, 96 

NEOPARASITIDAE, 54, 72, 74 

Neoparasitus. 73 

Neophyllobius. 205, 206 

Neopodocinum, 69 

Neoribates, 433 



Neorihatula, All 

Neorizetes, 433 

Neoroqueella, 319 

Neoschongastia, 256 

Neoseius, 106 

Neosmaris, 238, 239 

Neotanaupodus, 250 

Neoteneriffiola, 224 

Neotetranychus, 213 

Neothrombium, 251 

Neotorrenticola, 296 

NEOTORRENTICOLIDAE, 262, 266, 

296 
Neotrombicula, 256 
Neotrombidium, 249 
neotropica (Labidostomma), 186 
Neotydeus, 189 
Neotyrellia, 299 
Neoxystonotus, 314 
nerve, 15, 30, 31, 32 
nervosus (Galumna), 431 
Nesiotizetes, 424 
net, 9 

Neumania, 306 
NEUMANIINAE, 306 
Neiimannia, 382 
Neumanniella, 382 
neurotropic virus, 87 
Neuteria, 123 
Nicoletiella, 185 
nicollei (Ornithodoros), 139 
nidulans (Harpirhynchus), 231 
nigra (Galumna), 431 
Nilotonia, 292 
NILOTONIINAE, 292 
Niphocepheus, 413 
Nodipalpus, 358 
Noerneria, 183 
Nosomma, 143 
NOTASPIDIDAE, 392, 427 
Notaspis, 427 
Notaspis, 122 
Nothotrombicula, 251 
Nothroholaspis, 68 
Nothrus, 404 
Notoedres, 363, 365 
Notomideopsis, 314 
Notophallus, 175 
NOTOSTIGMATA, 12, 13, 14, 18, 20, 

21, 29, 32, 36 
NOTOTHROMBIINAE, 246, 247, 249 
Notothrombium, 249 
nova-scotiae (Mediolata), 205 
Novophytoptus. 150 
Novotrombicula, 257 
nudus (Cytodites), 367 
Nummuhis, 122 
Nuttalliella, 140 
NUTTALLIELLIDAE, 137, 140 



Index 



455 



Nyangalla, 307 
Nycteridocoptes, 363 
nymph, 14, 34, 43, 51, 52 

oblonga (Bdella), 181 

obtusus (Pterolichus), 384 

obvius (Galumna), 431 

ocellus, 32 

Octohydryphantes, 282 

Octolundbladia, 283 

Octomegapus, 301 

Octomideopsis, 314 

Octothyas, 283 

Ocypete, 249 

OCYPETINAE, 247, 249 

Odontacarus, 255 

ODONTOSCIRINAE, 179, 180 

Odontoscirus, 180 

Oehserchestes, 198 

Oenoschongastia, 257 

oil, 10 

Olabidocarpus, 277 

Olafsenia, 348 

OLAFSENIIDAE, 323, 348 

oleivorus (Phyllocoptruta), 157 

Oligonychus, 213 

Olodiscus, 119 

Ologamasellus, 73 

Ologamasus, 73 

Oloiphis, 93 

Ololaelaps, 95 

Olopachys, 70 

Olouropoda, 122 

Ommatocepheus, 413 

Onchodellus, 70 

ONYCHOPALPIDA, 23, 27, 34, 36 

Oocarpais, 67 

Ophidilaelaps, 96 

Ophiomegistus, 133 

Ophionyssus, 85 

Ophiopneumicola, 79 

Ophioptes, 229, 230, 231 

OPILIOACARIDAE, 37 

Opilioacarus, 37 

opisthosoma, 12, 13, 14, 29 

Oplitis, 122 

Oppia, 410 

Oppiella, 410 

Opsereynetes, 186, 187 

optic nerves, 32 

Optis merremi, 60 

Oribata, 410 

ORIBATEI, 10, 14, 30, 31, 33, 320, 387 

Oribatella, 425 

ORIBATELLIDAE, 392, 425 

oribatid, 19, 34 

Oribatodes, 412 

Oribatula, 421 

ORIBATULIDAE, 392, 420 



Oribella, 411 
Oribotritia, 437 
Oripoda, 419 
ORIPODIDAE, 392, 419 
ornamentation, 14, 15 
Ornithodoros, 138 • 
ornithosis, 81 
Oromurcia, 424 
Orthohalarachne, 77 
Otobius, 138 
Otocentor, \A1 
Otocepheus, 412 
Otodectes, 371, 373 
Oudemansiella, 85 
Oudemansium, 351 
Oulenzia, 342 
OULENZIIDAE, 322, 342 
Oustaletia, 382 
ovary, 33 

ovatus (Adoristes), 417 
oviduct, 33 
oviparous, 33 
ovipositor, 33 
ovis (Chorioptes), 373 
ovis (Psorergates), 231 
ovis (Psoroptes), 371 
ovis (Sarcoptes), 365 
ovoviviparous, 33 
OXINAE, 294 
Oxopsis, 282 
Oxus, 294 
Oxypleurites, 151 

Pachyglyphus, 331 

PACHYGNATHIDAE, 172, 199 

Pachygnathus, 13, 200 

Pachylaelaps, 70 

PACHYLAELAPTIDAE, 54, 69 

Pachylaella, 70 

Pachylichus, 374 

Pachyseius, 73 

pacifica (Labidostomma), 186 

pacificus (Tenuipalpus), 222 

pacificus (Tetranychus), 218 

PALAEACARIDAE, 389, 393, 394 

PALAEACARINAE, 395 

Palaeacarus, 395 

pallida (Rhagidia), 183 

pallidus (Tarsonemus), 169 

palmarum (Rhynchophorus), 161 

palp, 23, 24, 31 

Palpoboophilus, 143 

Panisellus, 283 

Panisoides, 283 

Panisopsis, 284 

Panisus, 283 

Panoplia, 185 

Papilloporus, 283 

Parabrachypoda, 311 



456 



Index 



Paracarus, 38 

Parachyzeria, 250 

paradoxa (Acomatacarus), 257 

Paradoxiphis, 95 

paradoxus (Tympanospinctus), 63 

Parakalumma, 433 

PARAKALUMMIDAE, 393, 432 

Parakoenikea, 307 

paralabra, 20, 41 

Paralaelaps, 70 

Paralges, 382 

Paralimnesia. 298 

Paralimnochares, 278 

Paraliodes, 411 

paralysis, 144 

Paramansia, 354 

PARAMEGISTIDAE, 130, 134 

Paramegistus, 134 

Paraneonyssus, 81 

PARANTENNULIDAE, 130 

Parantennulus, 130 

Parapelops. 429, 430 

Paraphytoptus, 150 

Pararoqueella, 319 

Paraschelobates, 422 

Paraschizobates, 300 

Paiaschoiigastia, 256 

Parasitalbia, 312 

Parasitellus, 67 

parasitic, 61 

parasites. 8 

PARASITIDAE. 26, 54, 57, 66, 94 

PARASITIFORMES, 40 

Parasitus, 57, 66 

parasitica (Ensliniella), 344 

Parasoldanellonyx. 273 

Parateneriffia, 224 

Paratetranychus, 213 

Parathyas. 283 

Paratrombium, 251 

PARATYDEIDAE. 171, 188 

Paratydeus, 189 

Parawenhoekia, 239 

Paraxonopsella, 311 

Paraxystonotus, 314 

Parazercon, 104 

Parazetes, 428 

Parerythraeus, 239 

Pareylais, 279 

Parholaspis. 69 

PARHYPOCHTHONIDAE, 394 

PARHYPOCHTHONIINAE, 394 

Parhypochthonius. 13, 395 

parkeri (Ornithodoros), 136 

parthenogenetic, 33 

Partnunia, 281 

Partnuniella, 281 

parvus (Cunaxoides), 194 

Passalacarus, 126 



PASSALIDAE, 103 

Passalobia, 103 

Passalozetes, 413 

patavina (Trematura), 114 

Paulitzia, 123 

Pavania, 164 

pectinatus (Cunaxoides), 194 

PEDICULOCHELIDAE, 321, 325 

Pediculochelus, 325 

Pediciiloides, 164 

PEDICULOIDIDAE, 159, 164 

Pediculopsis, 165 

pedipalp, 12, 19, 20, 21, 23, 24, 30, 34, 36, 

41 
Pedotrombidium, 249 
Peletiphis, 93 
PELOPIDAE, 392, 429 
Peloppia, 411 
PELOPPIIDAE, 411 
Pelops, 429, 430 
Pelopsis. 429, 430 
Peloptulus, 429, 430 
Peloribates, 428 
penis, 33 

Pentagonella, 256 
Pentalbia, 312 
Pentamerismus, 221 
Pentatax, 305 
PENTHALEIDAE, 174 
Penthaleus, 175 
Penthaleus, 111 
Penthalodes, 177 
PENTHALODIDAE, 172, 177 
Percanestrinia, 354 
Pergalumma, 431 
Pergamasus, 67 
Peridromotritia, 438 
Periglischrus, 63 
Periphis, 73 

peritreme, 30, 31, 34, 41, 43 
Periohmannia, 396, 397 
persicus (Argas), 139 
Petiohirus, 318 
Petralycus, 199, 200 
Petrobia, 213 
Petzschia, 331 
PHANOLOPHINAE, 243 
Phanolophus, 243 
pharynx, 27, 28. 30 
phase-contrast, 1 1 
Phaulocylliba, 120 
Phaulodiaspis, 120 
PHAULODINYCHIDAE, 109, 119 
Phaulodinychus, 120 
Phauloppia, 410 
phenol, 10 

phoenicis (Brevipalpus), 222 
PHOCIDAE, 77 
Photia, 354 



Index 



457 



Phrynacarus, 256 
PHTHIRACARIDAE, 393, 436 
PHTHIRACARINAE, 437 
Phthiracarus, 437 
Phthiroides, 165 
Phtiracarulus, 438 
Phylacozetes, 427 
Phyllhermannia. 404 
Phyllocoptes, 150 
PHYLLOCOPTIDAE, 148 
PHYLLOCOPTINAE, 149, 150 
Phyllocoptruta, 151 
Phyllocoptyches, 151 
phylloides (Demodex), 237 
Phyllotegeus, 411 
Phyllotetranychus, 221 
Phyl!otrombidium, 247 
phylogeny, 34 
phylum, 34 
Phymalod.'scus, 119 
Physalozeicon, 133 
Phytoiacobsonia, 95 
PHYTOPTINAE. 149 
PHYTOPTIPALPIDAE, 25, 148, 

211, 220 
Phytoptipalpus, 148, 221 
Phytoptochetus. 150 
Phytoptus, 149 
PHYTOSEllDAE, 55, 87, 90 
PHYTOSEllNAE, 88 
Phytoseius, 88 
Picobia, 229, 230 
pigeon, 86 
Piersigia, 280 
PIERSIGIINAE, 280 
p gment, 14 
Pilizetes, 431 
Pilolebertia, 293 
Pilolimnesia, 298 
pilosus (Paratetranychus), 214 
PUneliaphiloides, 208 
Pimeliaphilus, 208 
Pimelofia, 160 
pinicola (Eupalopsis), 205 
PINNIPEDIA, 77 
Piona, 308 
Pionacercopsis, 309 
Pionacercus, 309 
PIONAE, 261, 262 
PIONATACINAE, 307 
Pionatax, 307 
Pionella, 309 
PIONELLINAE, 309 
PIONIDAE, 262, 268, 307 
Pionides, 309 
PIONINAE, 308 
Pionopsis, 309 
Pirapampa, 319 
pirifoliae (Epitrimerus), 152 



pityriasis, 374 

Placobates, 300 

Placothyas, 283 

plague, 83 

planicornis (Pelops), 430 

PLANODISCIDAE, 109, 112 

Planodiscus, 112 

Plasmobates, 416 

plate 

anal, 19, 27, 42, 43 
coxal, 42 
dorsal, 19, 42, 43 
endopodal, 42, 43, 53 
epigyinal, 42, 43, 53 
hysterosomal, 18 
jugular, 42, 43 
lateral, 42, 43, 53 
median, 42, 43 
metapodal, 42, 43 
metasternal, 42, 43. 53 
ocular, 19 
parapodal, 42, 43 
peritremal, 42, 43 
171, praeendopodal, 42 

propodosomal, 18, 19, 31 
secondary, 19 

sternal, 14, 18, 19, 42, 43, 53 
stigmal, 29 

ventral, 41, 42, 43, 53 
Plategeocranus, 413 
platelet, 43 

PLATEREMAEIDAE, 390, 416 
Plateremaeus, 416 
Platylaelaps, 70 
Platyliodes, 405 
Platylophus, 239 
Platymamersopsis, 289 
Platynothrus, 404 
Platyphytoptus, 151 
Platyseius, 89 
Platyseta, 249 
Platytetranychus, 214 
Rlatytrombidium, 249 
Plaumannia, 316 
PLAUMANNIINAE, 316 
Plesialges, 380 
Plesiothyas, 284 
" Pleuronectocelaeno, 128 
Plutarchia, 382 
Pneumolaelaps, 94 
Pneumonyssus, 77 
PNEUMOPHIONYSSINAE, 78, 79 
Pneumophionyssus, 79 
Pneumotuber, 11 
Podaia, 205 

PODAPOLIPODIDAE, 25, 148, 159 
podapolipophagus (Pimeliaphilus), 207, 

208 
Podapolipus, 160 



458 



Index 



PODOCININAE, 88, 89 

Podocinum, 89 

Podoglyphus, 330 

Podolaelaps, 95 

podosoma, 12 

Poilofhronihiiini, 249 

POECILOCHIRIDAE, 53, 57 

Poecilochirus, 57 

Poecilochthonius, 402 

poils proprement dits, 16 

poison, 39 

POLLICIPALPINAE, 307 

Pollicipalpus, 307 

Polyaspidella, 110 

POLYASPIDAE, 105, 107 

POLYASPINIDAE, 106, 107 

Polyaspinus, 107 

Polyaspis, 107 

Polyatacides, 305 

Polyatax, 305 

Polydisca, 251 

Polyhydryphantes, 283 

Polymegapus, 301 

Polypterozetes, 411 

Pomerantzia, 206 

POMERANTZIIDAE, 174, 206 

Pontacarus, 272 

Pontarachna, 295 

PONTARACHNIDAE, 259, 262, 266, 

295 
Pontoppidania, 332 
PONTOPPIDANIINAE. 330, 332 
Popilius disjunctus, 46 
pores, 14, 32, 42, 43 
Porobelba, 408 

POROHALACARINAE, 272, 274 
Porohalacarus, 272 
Poroliodes, 406 
Porolohmannella, 272 
Povelsenia, 330 
Praeparasitus, 74 
praeliosa (Bryobia), 219 
pre-oral, 12 
preparation, 9 
preserved, 4 
pretarsus, 41 
Prholaspina, 69 
Procaeculus, 210 
Procericola, 354 
procrustidis (Photia), 354 
proctodaeum, 27 
Proctolaelaps, 95 
Proclophyllodes, 384 
PROCTOPHYLLODIDAE, 325, 385 
Proctotydaeus, 191, 192 
PRODINYCHIDAE, 109, 116 
Prodinychus, 116 
Prolabidocarpus, 377 
prominens (Smaris), 243 



Pronecupulatus, 192 

Pronematus, 191, 192 

Propelops, 429, 430 

Propeschelobates, 424 

propodosoma, 12, 13, 17, 30 

Prosopodectes, 363 

PROSTIGMATA, 13, 19, 30, 34, 146, 

147, 170 
prostigmatid, 34 
Protacarus, 175 
Protalges, 380 

protea (Pseudocheylus), 226 
Protereunetes, 175 
proterosoma, 12, 13, 30 
Proteylais, 279 
Protocepheus, 412 
Protokalumma, 433 
Prololaelaps, 64 
Protolichus, 381, 383 
Protolimnesia, 298 
PROTOLIMNESIINAE, 298 
Protomyobia, 230 
protonymph, 33 
Protonyssus, 85 
ProtonyssLis, 383 
Protoplophora, 435 

PROTOPLOPHORIDAE, 18, 393, 434 
Protoribates, 428 
Protoschelobates, 422 
Prototritia, 435 
PROTOUROPODIDAE, 110 
Protzia, 281 
Protziella, 281 

PROTZIIDAE, 262, 263, 280 
Prowichmannia, 359 
Prozercon, 105 
Psamnogalumna, 431 
Pseudalges, 385 
Pseudalloptes, 383 
Pseudamansia, 354 
Pseudobryobia, 214 
Pseudocepheus, 413 
PSEUDOCHEYLIDAE, 173, 224 
PSEUDOCHEYLINAE, 225 
Pseudocheylus, 225, 226 
pseudocuneatus (Brevipalpus), 222 
Pseudofeltria, 308 
Pseudogiebelia, 383 
Pseudohydryphantes, 289 
PSEUDOHYDRYPHANTIDAE, 262, 

265, 289 
Pseudokoenikea, 307 
Pseudokongsbergia, 312 
Pseudolaelaps, 96 
Pseudolebertia, 293 
PSEUDOLEPTIDAE, 220 
Pseudoleptus, 221, 222 
Pseudopachys, 74 
PSEUDOPARASITIDAE, 54, 74 



Index 



459 



Pseudoparasitus, 74 
Pseudosperchon, 291 
pseudostigmata, 17, 30, 31, 35, 320 
pseudostigmatic organ, 31, 35, 159, 320, 

321, 387 
Pseudotarsonemoides, 169 
Pseudotorrenticola, 295 
Pseudotritia, 438 
Pseudouropoda, 122 
Pseudoxus, 294 
Psoralges, 376 
PSORALGIDAE, 324, 375 
Psorergates, 229, 230 
Psoroptes, 370, 371 
psoroptid, 72 
PSOROPTIDAE, 324, 370 
Psoroptoides. 380 
Pteralloptes, 380 
PTEROCHTHONIIDAE, 400 
Pterochthonius, 402 
Pterocolus, 385 
Pterodectes, 385 
PTEROLICHIDAE, 380 
Pterolichus, 383 
Pteronyssus, 383 
Pterophagus, 385 
Pteropms, 63 
Pterygodes, 143 
Pterygosoma, 208 

PTERYGOSOMIDAE, 19, 173, 207 
Ptilolophus, 239 
Ptilonyssus, 81 
Ptochares, 133 
PTYCTIMA, 19, 387 
Ptylonyssoides, 81 
pulvillus, 23 

pulvinar (Nanorchestes), 199 
Puncticentor, 142 
PVA, 10 

Pyemotes, 14. 164 
PYEMOTIDAE, 159, 164 
Pygmephorus, 165, 166 
Pygmodispus. 163 

Q fever, 139, 145 

Quadracus, 152 

quercus (Diarthrophallus), 103 

Rad, 97 
Radfordia, 230 
Radfordiella, 86 
radula-like organ, 20, 36 
Raillietia, 75 

RAILLIETIDAE, 54, 75, 91 
Rallinyssus. 81 
Ranautonia, 293 
Raoiella, 221 

RAPHIGNATHIDAE, 174, 203 
Raphignathus, 204 



Raphitydeus, 192 
ratti (Myobia), 231 
raulti (Pediculochelus), 326 
Recifella, 307 

reconditus (Podapolipus), 161 
record, 4 

rectangulatum (Microgynium), 51 
rectum, 27, 28 
redberry mite, 158 
reflector, 7 
relapsing fever, 139 
reproductive system, 33 
Resinacarus, 165 
respiratory system, 29, 30 
Retetydeus, 192 
Rhabdohydrachna, 277 
Rhabdotobates, 300 
Rhagidia, 183 
Rhagidia organ, 32, 182 
RHAGIDIIDAE, 31, 32, 172, 181 
Rhagina, lid 
Rhinacarns, 11, 81 
Rhinixodes, 11 
Rhinoecius, 81 
RHINONYSSIDAE, 55, 79 
Rhinonyssoides, 81 
Rhinonyssus, 80 
Rhinophoracarus, 318 
RHINOTHROMBIINAE, 247, 249 
Rhinothrombium, 249 
Rhipicentor, 143 
RHIPICEPHALINAE, 142, 143 
Rhipicephalus, 143 
RHIZOGLYPHINAE, 330 
Rhizoglyphus, 330 
Rhodacarellus, 59 
1^ RHODACARIDAE, 53, 59 
Rhodacaropsis, 59 
Rhodacarus, 41, 59 
Rhodaxes, 213 
Rhombognathides, 271 
RHOMBOGNATHINAE, 271, 273 
Rhombognathus, 271 
Rhyncaphytoptus, 152 
Rhyncheylais, 280 
RHYNCHOHYDRACARIDAE, 262, 

263, 275 
Rhynchohydracarus, 276 
Rhyncholimnochares, 278 
RHYNCHOLIMNOCHARINAE, 278 
Rhyncholophus, 239 
rhynchophori (Tetrapolipus), 161 
Rhynchoribates, 411 
Riccardoella, 187 
ribis (Cecidophyes), 158 
ricinus (Ixodes), 144 
rickettsia, 257 
rickettsial pox, 87 
Riedlinia, 257 



460 



Index 



Riemia, 343, 344 

Rivobates, 300 

Rivoltasia, 374 

Rochanyssus, 81 

Rocky Mountain spotted fever, 139, 144 

Rohaiiltia, 248 

rollinati (Labidocarpus), 378 

Rondaniocarus, 221 

Roqueella, 319 

Rosenhofia, 194 

Rosensteinia, 354 

rostratus (Eutrombidium), 252 

Rostrozetes, 428 

rudis (Ornithodoros), 139 

Rusetria, 295 

Rusetriella, 295 

Rutacarus, 292 

RUTRIPALPIDAE, 262, 264, 287 

Rutripalpus, 288 

Saintdidieria, 72 

saitoi (Dermatophagoides), 375 

salivary gland, 28 

Sammonica, 383 

Sancassania, 331 

Sandenia, 433 

sanguineus (Allodermanyssus), 87 

SAPROGLYPHIDAE, 322, 326 

Saproglyphus, 327 

sarcina (Trombicula), 258 

Sarcohorus, 230 

Sarcopteiinus, 230 

Sarcopterus, 230 

Sarcoptes, 362 

SARCOPTIDAE, 324, 362 

SARCOPTIFORMES, 15, 16, 18, 23, 27, 

29, 30, 31, 35, 40, 320 
saucer, 5 
Sauracarella, 255 
Sauriscus, 257 

savignyi (Ornithodoros), 139 
scabiei (Sarcoptes), 363 
SCALOTHROMBIINAE, 250 
Scalothrombiiim, 250 
scalp, 374 

Scapheremaeus, 407 
Scaphothrix, 208 
Scaptognathus, 272 
Scatogiyphus, 338 
Schadeela, 307 
SCHADEELLINAE, 307 
Scharfenbergia, 227 
Schelleuhema, 228 
Scheloribates, 422 
SCHELORIBATIDAE, 420 
scheremetewskvi (Dermatophagoides), 

374 
Schizobates, 300 
Schizocarpus, 25, 377 



Schizocoptes, 377 

Schizodiplogynium, 126 

SCHIZOGYNllDAE, 124, 129 

Schizogynium, 129 

Schizohydrachna, 277 

Schizotetranychus, 212, 214 

Schmiedleinia, 213 

Schongastia, 257 

Schongastiella, 255 

Schubartella, 300 

Schwiebea, 331 

Scirula, 194 

Scirus, 179. 180, 193 

Scissuralaelaps, 96 

sclerites, 18, 34 

Sclerosmaris, 243 

Scolotydaeus, 189 

scorpion, 209 

scrub typhus, 257 

SCUTACARIDAE, 159, 162 

Scutacarus, 162 

Scutohydrachna, 277 

Scutoribates, 413 

Scutosperchon, 291 

Scutovertex, 413 

scutum, 19 

Scyphius, 183 

seals, 77 

Sebaia, 202 

seghettii (Protoschelobates), 422 

segment, 11, 12 

Seiodes, 105 

Seiopsis, 89 

Seiulus, 89 

Seius, 89 

Sellea, 359 

seminal receptacle, 33 

sense organs, 31 

sensillae, 17, 31 

Sennertia, 352 

Septanychus, 214 

sericeum (Smaris), 243 

Sericothrombium, 247 

Serpenticola, 85 

Serrariiis, 419 

Sessiluncus, 74 

seta, 15, 16. 17, 18, 22, 23, 24, 26, 31, 32, 

41, 42, 43, 52, 53 
setirostris (Cunaxa), 194 
Setoptus, 149 

sexclavatus (Saintdidieria), 72 
sexual reproduction, 33 
sheep, 258 

sheldoni (Aceria), 157 
shield, 18. 19 
Siblyia. 228 

SIERRAPHYTOPTINAE, 149, 150 
Sierraphytoptus, 150 
Sigthori, 292 



Index 



461 



silk, 28, 181, 211, 228 

similis (Liebstadia). 422 

SIMOGNATHINAE, 272, 274 

Simognathus, 272 

simplex (Myobia), 231 

Simplinychus, 214 

siro (Acarus), 234, 335 

Siteroptes, 165 

SMARIDIIDAE, 13, 173, 241 

SMARIDIINAE, 243 

Smariidia, 242 ' 

Smaris, 242 

Smaris, 245 

Sminthurus viridis, 180 

smuts, 153 

snake, 56, 60, 79, 138 

Snartia, 227 

snout, 19 

snout mite, 178 

Soldanellonyx, 273 

solenidien, 17 

Solenozetes, 416 

Sommatricola, 81 

South African tick-bite fever, 145 

SPELAEORHYNCHIDAE, 13, 53, 61 

Spelaeorhynchus, 61 

Spelaeothrombium, 249 

SPELEOGNATHIDAE, 171, 189 

Speleognathus, 189 

Speleorchestes, 13, 26, 198 

Speotrombicula, 257 

Sperchon, 290 

SPERCHONIDAE, 262, 265, 290 

Sperchonopsis, 291 

spermatophores, 21, 23 

spermatozoa, 33 

Sphaerobates, 424 

SPHAEROCHTHONIIDAE, 400 

Sphaerochthonius, 400 

Sphaerogastra, 383 

Sphaerolaelaps, 70 

SPHAEROLICHIDAE, 172, 196 

Sphaerolichus, 197 

Sphaerolophus, 240 

Sphaeroseius, 73 

Sphaerotarsus, 243 

Sphaerozetella, 425 

Sphaerozetes, 424 

spider mites, 22, 211 

Spinibdella, 179 

SPINIBDELLINAE, 179 

spinipes (Glycyphagus), 353 

Spinolaelaps, 85 

SPINTURNICIDAE, 54, 62 

Spinturnix, 63 

spirochaets, 1 39 

splendens (Trombicula), 257 

spirifex (Tarsonemus), 169 

stabularis (Eulaelaps), 15 



stager i (OrnithoJoros), 139 
Stamfordia, 95 

Staphlococcus pyogenes albus, 236 
Steatonyssus, 86 
Steganacarus, 437 
Stenosternum, 46 
Stereoglyphus, 331 
Stereotydeus, 177 
Sternalixodes, 142 
sternites, 18 
Sternostoma, 81 
Sternostomum, 81 
Stictozetes, 431 
stigma, 29, 30 
STIGMAEIDAE, 203 
Stigmaeodes, 205 
Stigmaeopsis, 214 
Stigmaeus, 205 
stigmal horn, 30 
stigmata, 34, 41, 43 
Stigmocheylus, 225, 226 
St. Louis encephalitis, 86 
stomadaeum, 27 
Stomoxys calcitrans, 166 
Storchia. 205 
Storkania, 424 
Stratiolaelaps, 94 
Strieremaeus. 411 
Stroemia, 352 

sturni (Speleognathus), 190 
Stygohalacarus, 273 
Stygohydracarus, 316 
Stygomonia, 269 
STYGOMONIDAE, 269 
STYGOTHROMBIINAE, 247, 250 
Stygothrombium, 250 
stylifera (Trematurella), 114 
Stylochirus, 95 
Stylohygrobates, 300 
stylophore, 211, 220 
Styloribates, 422 
Stvlotvdeiis, 191 
Subalbia, 312 
Subaturus, 312 
subclass, 34 
Subcorticacarus, 300 
Submiraxona, 312 
^ Subneumania, 306 
suborder, 34 
subphylum, 34 
Suctobelba, 411 
Suctobelbella, 411 
Suctobelbila, 411 
Suidasia, 331 
suis (Sarcoptes), 365 
Sumatralbia, 311 
superba (Lorryia), 192 
Svalbardia, 420 
swazianus (Erythraeus), 240 



462 



Index 



sylviarum (Bdellonyssus), 87 
Symbiotes, 371 
Symplectoptes, 367 
Syncaligiis, 204 
Syneylais, 280 

SYNGYNASPIDAE, 130, 131, 132 
Syngynaspis, 131 
Syringobia. 383 
SYRINGOBIIDAE, 380 
Syringophilus, 229, 230, 231 

tactile organs, 31 

takeuchi (Dermatophagoides), 341, 375 

talaje (Ornithodoros), 139 

Tanaognathella, 307 

Tanaognathus, 307 

Tanaupodaster, 250 

TANAUPODASTERINAE, 247, 250 

TANAUPODINAE, 246, 250 

Tanaupodus, 250 

tapeworm, 352, 387, 388, 413, 417, 422, 

425, 428, 430, 431 
tardus (Pelops), 430 
Tarsocheylus, 225, 226 
Tarsolarkus, 228 
Tarsonemella, 168, 169 
tarsonemid, 12, 33 
TARSONEMIDAE, 159, 168 
TARSONEMINI, 18, 30, 146, 147, 159 
Tarsonemoides, 165 
Tarsonemus, 169 
Tarsopolipus, 160 
Tarsotomus, 25, 228 
tarsus, 17, 21. 23, 24, 25, 31,41 
Tartarothvas, 284 
TARTAROTHYASINAE, 284 
taurus (Cunaxa), 194 
Tecomatlana, 257 
Tectocepheus, 413 
Tectocymba, 407 
Tectopelops, 429, 430 
Tectopenthalodes, 177 
Tectoribates, 426 
tectostracum, 13 
Tectotydeus, 191 
tectum, 19, 20, 41 
Tegeozetes, 424 
Tegeocranellus, 413 
Tegeocranus, 412 
tegeocranus (Xenillus), 413 
Tegonotus, 152 
Tegopalpus, 221 
Tegoribates, 430 
Teincoptes, 363 
telarius (Tetranychus), 218 
Teleioliodes, 406 
telofemur, 23, 25 
Tencateia, 228 
tenem hair, 25, 211 



Teneriffia, 224 

TENERIFFIIDAE, 173, 223 

Teneriffiola, 224 

Tenuiala, 420 

TENUIALIDAE, 392, 420 

Temiicnis, 214 

TENUIPALPIDAE, 220 

Tenuipalpus, 221 

Teratothyas, 284 

TERATOTHYASINAE, 284 

tergite, 18, 19 

terminalis (Mediolata), 205 

terminology, 11 

Termitacanis, 95 

termites, 56 

TERPNACARIDAE, 172, 201 

Terpnacarus, 201, 202 

Terrazetes, 424 

testis, 33 

Testudacarus, 295 

Tetra, 152 

Tetrabates, 300 

tetracaudata (Grandiella), 354 

Tetmgonyssus, 85 

Tetrahydrachna, 277 

Tetralimnesia, 298 

Tetramegapus, 301 

Tetraneumania, 306 

Tetranobia, 213 

TETRANYCHIDAE, 10, 146, 173, 211, 

234 
Tetranychina, 214 
Tetranychus, 212, 213 
Tetranycopsis, 211, 214 
Tetrapiona, 308 
TETRAPODILI, 20, 146, 148 
Tetrapolipus, 160, 161 
Teutonia, 290 

TEUTONIIDAE, 262, 265, 289 
texana (Geckobiella), 209 
Texas cattle fever, 144 
Thalassarachna, 271 
Thamnacarus, 399 
Thamnacus, 152 
Thaumatotrombium, 250 
Thecarthra, 383 
Therismoptes, 165 

THERMACARIDAE, 262, 264, 286 
Thermacarus, 287 
Thinoseius, 89 
Thinozercon, 99 
THINOZERCONIDAE, 98 
THINOZERCONINA, 43, 44, 98 
Thonia, 301 

Thoracohygrobates, 301 
Thoracophoracarus, 318 
Thoribdella, 180 ^ 

Thrichocylliba, 115 
Thyas, 283 



Index 



463 



Thyasella, 284 

Thyasides, 284 

THYASINAE, 283 

Thyopsis, 284 

Thyreophagus, 327, 329, 331 

tibia, 17, 21, 23, 24, 25 

tick. 15, 19, 20, 21, 22, 31, 33, 34, 137, 

144 
tidal zone, 339 
tigipioensis (Apolonia), 258 
Tignyia, 250 
Tiphys, 309 
TIPHYSINAE, 309 
Torpacarus, 399 
Tortonia, 344 
Toxopeusia, 135 
trachea, 29. 35, 387 

trachealis (Locustacarus), 160, 161, 162 
tracheole, 29 
Trachygamasus, 67 
Trachyhoplophora, 437 
Trachymolgus, 178, 179 
Trachyoribates, 424 
Trachytes, 106 
TRACHYTIDAE, 106 
TRACHYTINA. 43, 44, 105, 108, 111 
Trachyuropoda, 118 
TRACHYUROPODIDAE, 109, 118 
Tragardhacarus, 395 
tragardhi ( Kline kowstroemia), 135 
tragardhi (Neo-Oudemansia), 132 
tragardhi (Syngynaspis), 131, 132 
Tragardhula, 256 
trap. 8 

Travanyssus, 81 
tray, 5, 9 
Trematura, 113 
Trematurella. 114 
TREMATURELLIDAE, 109, 114 
TREMATURIDAE, 108, 109, 113, 114 
Trhypochthoniellus, 400, 402 
Trhypochthonius, 400, 402 
Triangulazercon, 105 
TRICHADENIDAE, 220 
Trichadenus. 221 
Tricheremaeus, 411 
Trichobius, 311 
Trichodinychus. 117 
TRICHODIPLOGYNIINAE, 125 
Trichodiplogynium, 126 
Trichoecius. 377 
Tricholaelaps. 96 
Tricholocelaeno, 69 
Trichoribates, 425 
Trichostigma, 150 
Trichotarsus, 351 
Trichothyas, 284 
Trichouropoda, 123 
T rid ilaty dens, 192 



Tridiplogynium, 126 

trifolium (Olafsenia), 348 

Trigonholaspis, 69 

Trimalaconothrus, 403 

trinotum (Myialgopsis), 369 

Triophtydeus, 192 

Trisetica, 257 

Tristomus, 89 

Tritegeus, 413 

Tritia, 437 

tritonymph, 33 

tritosternum. 18, 41, 42 

Trixacarus, 363 

Trizerconoides, 105 

Trizetes, 41 1 

trochanter, 23, 25 

Troglobdella, 180 

Troglohalacarus, 272 

Trombella, 250 

TROMBELLINAE, 246, 250 

Trombicula, 256, 257 

TROMBICULIDAE, 13, 19, 251, 253, 

254, 174 
TROMBICULINAE, 254, 256 
TrombicuHndus, 256 
Trombiculoides, 256 
TROMBIDIFORMES. 14, 16, 18, 24, 25, 

27, 28, 29, 30, 31, 35, 40, 146, 147 
TROMBIDIIDAE. 19, 146, 174, 245, 246, 

251 
TROMBIDIINAE, 246, 247 
Trombidium, 247 
Tropacarus, 437 
Trouessartia, 385 
Truncaturus, 318 
tsutsugamushi, 257 
Tuberemaeus, 411 
Tubophora, 298 
tularemia, 83, 139, 145 
tulipae (Aceria), 158 
Tumescoptes, 152 
Tumidalvus, 402 
Tur, 85 

Turbinoptes, 374 
turicata (Ornithodoros), 139 
turtles, 138 
Tydaeolus, 192 
TYDEIDAE, 171, 190 
Tydeus, 191 
Tympanomegapus, 301 
Tympanospinctus, 63 
typhae (Tarsonemus), 168 
Typhlodromus, 89 
Typhlothrombium, 250 
typhus, 83 
Tyrellia, 299 
TYRELLIINAE, 299 
Tyroborus, 330 



464 



Index 



TYROGLYPHIDAE, 327 

Tyroglyphopsis, 331 
Tyroglyphus, 330 
Tyrolichus. 330 
Tyrophagus, 330 

ubiquitus (Pronematus), 192 

Udetaliodes, 404 

Ugandolaelaps, 96 

ulmi (Metatetranychus), 214, 217, 218 

uncinifer (Hyadesia), 340 

undulata (Vidia), 344 

Unduloribates, 426 

Unguizetes. 422 

Unionicola, 305 

UNIONICOLIDAE, 262, 267, 304 

Unionicolides, 305 

UNIONICOLINAE, 305 

urine, 9, 341, 375 

Uroboophilus, 143 

Urocyclella, 123 

URODIASPIDAE, 109, 117 

Urodiaspis, 117 

URODINYCHIDAE, 120 

Urodinychus, 121 

Urodiscella, 123 

Urodiscus, 121 

Uroiphis, 93 

Urojanetia, 118 

Urolaelaps, 117 

Uronothrus, 404 

Uroobovella, 123 

Uroplitana, 123 

Uroplitella, 122 

Uropoda, 122 

Uropoda, 122 

uropodid, 28, 34 

UROPODIDAE, 109, 121 

UROPODINA, 13, 18, 41, 43, 44, 105, 

108, 111, 114, 119 
Uropolyaspis, 119 
Uroseius, 106 
Urospina, 119 
Urosternella, 123 
Urozercon, 95 
urstigma, 244, 246, 254, 259 
urstigmata, 329 
uterus, 33 

Vaghia, 431 
vagina, 33, 43 
Valgothrombium, 249 
Valmontia, 332 
Varchia, 380 
Variatipes, 163 
Varroa, 95 
Vasates, 152 
vas deferens, 33 



Veigaia. 65 

VEIGAIAIDAE, 54, 65 

venter, 18 

ventral pore, 41 

ventricosus (Pyemotes), 165, 166 

ventriculus, 27, 28 

venustus (Dermacentor), 144 

veterinary 

ACARIDAE, 327 

ANALGESIDAE, 279 

ARGASIDE. 137 

CARABODIDAE, 413 

CERATOZETIDAE, 423 

CYTODITIDAE, 366 

DEMODICIDAE, 235 

DERMANYSSIDAE, 83 

DERMOGLYPHIDAE, 380 

EPIDERMOPTIDAE, 373 

GALUMNIDAE, 430 

HALARACHNIDAE, 76 

HAPLOZETIDAE, 428 

HOLOTHYRIDAE, 39 

IXODIDAE, 141 

LAELAPTIDAE, 92 

LAMINOSIOPTIDAE, 367 

LIACARIDAE, 417 

LISTROPHORIDAE, 376 

MYOBIIDAE, 229 

NOTASPIDIDAE, 427 

ORIBATULIDAE, 420 

PELOPIDAE, 429 

PROCTOPHYLLODIDAE, 384 

PSOROPTIDAE, 370 

RAILLIETIDAE, 75 

SARCOPTIDAE, 362 

TROMBICULIDAE, 253 
vials, 4 
Vidia, 344 
Viedebanttia, 332 
Vietsia, 284 
Villersia, 205 
virgata (Bdella), 181 
virginiensis (Galuman), 431 
vitis (Calepitrimerus), 157 
vitis (Eriophyes), 157 
vitis (Giardius), 362 
Vitznyssus, 81 

waitei (Tarsonemus), 169 
Walchia, 255 

WALCHIINAE, 254, 255 
Walterella, 111 
Walzia, 228 
wandernymph, 333 
Wandesia, 281 

wasmanni (Forcellinia), 338 
water mite, 15, 259 
Werthella, 272 



Index 



465 



Wettina, 309 

Whartonia, 255 

Wichmannia, 259 

Willania, 203 

Willmannia, 48 

Winterschmidtia, 346 

WINTERSCHMIDTIIDAE, 345 

Womersia, 256 

Womersleyia, 251 

Wuria. 318 

Wuiiella, 318 

Xenillus, 413 
Xenothrombium, 247 
Xolalges, 380 
Xoloptes, 383 
Xylobates, 428 
Xystonotus, 314 

yumensis (Tetranychus), 219 



Zercon, 104 
ZERCONIDAE, 104 
ZERCONINA, 43, 44, 104 
Zerconopsis, 89 
Zercoseius, 89 
Zetes, 430 
Zetobelba, 410 
Zetomimus, 422 
Zetomotrichus, 422 
Zetorchella, 418 
Zetorchestes, 418 
ZETORCHESTIDAE, 391, 415 
Zetsellia, 205 
Zonurobia, 208 
Zschachia, 359 
Zschokkea, 284 
Zuluacarus, 48 
Zwickia, 359 
Zygoribatula, 421 
Zygoseius, 89